PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (1058636)

Clipboard (0)
None

Related Articles

1.  Did the pandemic have an impact on influenza vaccination attitude? a survey among health care workers 
Background
Health care workers' (HCWs) influenza vaccination attitude is known to be negative. The H1N1 epidemic had started in mid 2009 and made a peak in October-November in Turkey. A national vaccination campaign began on November 2nd, 2009. Despite the diligent efforts of the Ministry of Health and NGOs, the attitudes of the media and politicians were mostly negative. The aim of this study was to evaluate whether HCWs' vaccination attitudes improved during the pandemic and to assess the related factors.
Methods
This cross-sectional survey was carried out at the largest university hospital of the Aegean Region-Turkey. A self-administered questionnaire with 12 structured questions was applied to 807 HCWs (sample coverage 91.3%) before the onset of the vaccination programme. Their final vaccination status was tracked one week afterwards, using immunization records. Factors influencing vaccination rates were analyzed using ANOVA, t-test, chi-square test and logistic regression.
Results
Among 807 participants, 363 (45.3%) were doctors and 293 (36.6%) nurses. A total of 153 (19.0%) had been vaccinated against seasonal influenza in the 2008-2009 season. Regarding H1N1 vaccination, 143 (17.7%) were willing to be vaccinated vs. 357 (44.2%) unwilling. The number of indecisive HCWs was 307 (38.0%) one week prior to vaccination. Only 53 (11.1%) stated that they would vaccinate their children. Possible side effects (78%, n = 519) and lack of comprehensive field evaluation before marketing (77%, n = 508) were the most common reasons underlying unwillingness or hesitation.
Among the 749 staff whose vaccination status could be tracked, 228 (30.4%) actually received the H1N1 vaccine. Some of the 'decided' staff members had changed their mind one week later. Only 82 (60%) of those willing, 108 (37%) of those indecisive and 38 (12%) of those unwilling were vaccinated.
Indecisive HCWs were significantly younger (p = 0.017). Females, nurses, and HCWs working in surgical departments were more likely to reject vaccination (p < 0.05). Doctors, HCWs working in medical departments, and HCWs previously vaccinated against seasonal influenza were more likely to accept vaccination (p < 0.05). Being younger than 50 and having been vaccinated in the previous season were important predictors of attitude towards pandemic influenza vaccination.
Conclusions
Vaccination rates increased substantially in comparison to the previous influenza season. However, vaccination rates could have been even higher since hesitation to be vaccinated increased dramatically within one week (only 60% of those willing and the minority of those indecisive were finally vaccinated). We speculate that this may be connected with negative media at the time.
doi:10.1186/1471-2334-11-87
PMCID: PMC3084177  PMID: 21473763
2.  The Effects of Influenza Vaccination of Health Care Workers in Nursing Homes: Insights from a Mathematical Model 
PLoS Medicine  2008;5(10):e200.
Background
Annual influenza vaccination of institutional health care workers (HCWs) is advised in most Western countries, but adherence to this recommendation is generally low. Although protective effects of this intervention for nursing home patients have been demonstrated in some clinical trials, the exact relationship between increased vaccine uptake among HCWs and protection of patients remains unknown owing to variations between study designs, settings, intensity of influenza seasons, and failure to control all effect modifiers. Therefore, we use a mathematical model to estimate the effects of HCW vaccination in different scenarios and to identify a herd immunity threshold in a nursing home department.
Methods and Findings
We use a stochastic individual-based model with discrete time intervals to simulate influenza virus transmission in a 30-bed long-term care nursing home department. We simulate different levels of HCW vaccine uptake and study the effect on influenza virus attack rates among patients for different institutional and seasonal scenarios. Our model reveals a robust linear relationship between the number of HCWs vaccinated and the expected number of influenza virus infections among patients. In a realistic scenario, approximately 60% of influenza virus infections among patients can be prevented when the HCW vaccination rate increases from 0 to 1. A threshold for herd immunity is not detected. Due to stochastic variations, the differences in patient attack rates between departments are high and large outbreaks can occur for every level of HCW vaccine uptake.
Conclusions
The absence of herd immunity in nursing homes implies that vaccination of every additional HCW protects an additional fraction of patients. Because of large stochastic variations, results of small-sized clinical trials on the effects of HCW vaccination should be interpreted with great care. Moreover, the large variations in attack rates should be taken into account when designing future studies.
Using a mathematical model to simulate influenza transmission in nursing homes, Carline van den Dool and colleagues find that each additional staff member vaccinated further reduces the risk to patients.
Editors' Summary
Background.
Every winter, millions of people catch influenza, a contagious viral disease of the nose, throat, and airways. Most people recover completely from influenza within a week or two but some develop life-threatening complications such as bacterial pneumonia. As a result, influenza outbreaks kill about half a million people—mainly infants, elderly people, and chronically ill individuals—each year. To minimize influenza-related deaths, the World Health Organization recommends that vulnerable people be vaccinated against influenza every autumn. Annual vaccination is necessary because flu viruses continually make small changes to the viral proteins (antigens) that the immune system recognizes. This means that an immune response produced one year provides only partial protection against influenza the next year. To provide maximum protection against influenza, each year's vaccine contains disabled versions of the major circulating strains of influenza viruses.
Why Was This Study Done?
Most Western countries also recommend annual flu vaccination for health care workers (HCWs) in hospitals and other institutions to reduce the transmission of influenza to vulnerable patients. However, many HCWs don't get a regular flu shot, so should efforts be made to increase their rate of vaccine uptake? To answer this question, public-health experts need to know more about the relationship between vaccine uptake among HCWs and patient protection. In particular, they need to know whether a high rate of vaccine uptake by HCWs will provide “herd immunity.” Herd immunity occurs because, when a sufficient fraction of a population is immune to a disease that passes from person to person, infected people rarely come into contact with susceptible people, which means that both vaccinated and unvaccinated people are protected from the disease. In this study, the researchers develop a mathematical model to investigate the relationship between vaccine uptake among HCWs and patient protection in a nursing home department.
What Did the Researchers Do and Find?
To predict influenza virus attack rates (the number of patient infections divided by the number of patients in a nursing home department during an influenza season) at different levels of HCW vaccine uptake, the researchers develop a stochastic transmission model to simulate epidemics on a computer. This model predicts that as the HCW vaccination rate increases from 0 (no HCWs vaccinated) to 1 (all the HCWs vaccinated), the expected average influenza virus attack rate decreases at a constant rate. In the researchers' baseline scenario—a nursing home department with 30 beds where patients come into contact with other patients, HCWs, and visitors—the model predicts that about 60% of the patients who would have been infected if no HCWs had been vaccinated are protected when all the HCWs are vaccinated, and that seven HCWs would have to be vaccinated to protect one patient. This last figure does not change with increasing vaccine uptake, which indicates that there is no level of HCW vaccination that completely stops the spread of influenza among the patients; that is, there is no herd immunity. Finally, the researchers show that large influenza outbreaks can happen by chance at every level of HCW vaccine uptake.
What Do These Findings Mean?
As with all mathematical models, the accuracy of these predictions may depend on the specific assumptions built into the model. Therefore the researchers verified that their findings hold for a wide range of plausible assumptions. These findings have two important practical implications. First, the direct relationship between HCW vaccination and patient protection and the lack of any herd immunity suggest that any increase in HCW vaccine uptake will be beneficial to patients in nursing homes. That is, increasing the HCW vaccination rate from 80% to 90% is likely to be as important as increasing it from 10% to 20%. Second, even 100% HCW vaccination cannot guarantee that influenza outbreaks will not occasionally occur in nursing homes. Because of the large variation in attack rates, the results of small clinical trials on the effects of HCW vaccination may be inaccurate and future studies will need to be very large if they are to provide reliable estimates of the amount of protection that HCW vaccination provides to vulnerable patients.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050200.
Read the related PLoSMedicine Perspective by Cécile Viboud and Mark Miller
A related PLoSMedicine Research Article by Jeffrey Kwong and colleagues is also available
The World Health Organization provides information on influenza and on influenza vaccines (in several languages)
The US Centers for Disease Control and Prevention provide information for patients and professionals on all aspects of influenza (in English and Spanish)
The UK Health Protection Agency also provides information on influenza
MedlinePlus provides a list of links to other information about influenza (in English and Spanish)
The UK National Health Service provides information about herd immunity, including a simple explanatory animation
The European Centre for Disease Prevention and Control provides an overview on the types of influenza
doi:10.1371/journal.pmed.0050200
PMCID: PMC2573905  PMID: 18959470
3.  Promotion of influenza vaccination among health care workers: findings from a tertiary care children’s hospital in Italy 
BMC Public Health  2015;15:697.
Background
The aims of this study were: a) to evaluate attitudes and practices of health care workers (HCWs) towards influenza vaccination and their opinion regarding a vaccination promotion toolkit; b) to estimate hospital HCWs’ influenza vaccination coverage rates (VC).
Methods
The Bambino Gesù Children’s Hospital (OPBG) is an academic hospital in Italy. Since 2009, free influenza vaccination is offered to HCWs during working hours. In October-December 2013, a communication campaign based on a standardized toolkit was conducted. In December 2013, we performed a cross-sectional survey in a sample of hospital wards, based on a self-administered questionnaire including participants’ characteristics; self-reported influenza vaccination history; reasons for vaccination or missed vaccination; opinion regarding the toolkit. Multivariable logistic analysis was used to assess independent predictors of influenza vaccination status. Annual VC for years 2009–2013 was estimated by using the number of seasonal influenza vaccine doses administered to HCWs as numerator, and the number of hospital HCWs as denominator.
Results
Out of 191 HCWs who participated in the survey, 35.6 % reported at least one influenza vaccination during their life; 6.8 % adhered to annual revaccination. Years of service and professional category were significantly and independently associated with vaccination (adjusted-OR: 2.4 for > 10 years of service, compared to < 5 years of service; adjusted-OR: 2.6 for physicians compared to nurses). Patient protection was the main reported reason for vaccination (34.3 %); considering influenza a mild disease was the main reason for non-vaccination (36.9 %); poor vaccine effectiveness was the main reason for missed annual revaccination (28.8 %). Overall, 75 % of respondents saw at least one promotion tool; 65.6 % of them found the information useful. Hospital VC decreased from 30 % in 2009, to 5 % in 2012. In 2013, VC was 14 %.
Conclusions
Satisfactory influenza VC in HCWs is hard to achieve. In 2013, along with the toolkit implementation, we observed an increase in HCWs’ vaccination coverage, nevertheless, it remained unsatisfactory. Tailored information strategies targeting nurses and recently employed HCWs should be implemented. Institution of declination statements, adding influenza vaccination to financial incentive systems, or vaccination requirements should also be considered to increase influenza VC among HCWs.
doi:10.1186/s12889-015-2067-9
PMCID: PMC4513703  PMID: 26204896
Influenza vaccine; Healthcare workers; Communication campaign; Attitudes
4.  "Will they just pack up and leave?" – attitudes and intended behaviour of hospital health care workers during an influenza pandemic 
Background
There is a general consensus that another influenza pandemic is inevitable. Although health care workers (HCWs) are essential to the health system response, there are few studies exploring HCW attitudes to pandemic influenza. The aim of this study was to explore HCWs knowledge, attitudes and intended behaviour towards pandemic influenza.
Methods
Cross-sectional investigation of a convenience sample of clinical and non-clinical HCWs from two tertiary-referral teaching hospitals in Sydney, Australia was conducted between June 4 and October 19, 2007. The self-administered questionnaire was distributed to hospital personal from 40 different wards and departments. The main outcome measures were intentions regarding work attendance and quarantine, antiviral use and perceived preparation.
Results
Respondents were categorized into four main groups by occupation: Nursing (47.5%), Medical (26.0%), Allied (15.3%) and Ancillary (11.2%). Our study found that most HCWs perceived pandemic influenza to be very serious (80.9%, n = 873) but less than half were able to correctly define it (43.9%, n = 473). Only 24.8% of respondents believed their department to be prepared for a pandemic, but nonetheless most were willing to work during a pandemic if a patient or colleague had influenza. The main determinants of variation in our study were occupational factors, demographics and health beliefs. Non-clinical staff were significantly most likely to be unsure of their intentions (OR 1.43, p < 0.001). Only 42.5% (n = 459) of respondents considered that neuraminidase inhibitor antiviral medications (oseltamivir/zanamivir) would protect them against pandemic influenza, whereas 77.5% (n = 836) believed that vaccination would be of benefit.
Conclusion
We identified two issues that could undermine the best of pandemic plans – the first, a low level of confidence in antivirals as an effective measure; secondly, that non-clinical workers are an overlooked group whose lack of knowledge and awareness could undermine pandemic plans. Other issues included a high level of confidence in dietary measures to protect against influenza, and a belief among ancillary workers that antibiotics would be protective. All health care worker strategies should include non clinical and ancillary staff to ensure adequate business continuity for hospitals. HCW education, psychosocial support and staff communication could improve knowledge of appropriate pandemic interventions and confidence in antivirals.
doi:10.1186/1472-6963-9-30
PMCID: PMC2661074  PMID: 19216792
5.  Predictive factors associated with the acceptance of pandemic and seasonal influenza vaccination in health care workers and students in Tuscany, Central Italy 
Human Vaccines & Immunotherapeutics  2013;9(12):2603-2612.
Assessing the beliefs and attitudes of Health Care Workers (HCW) to influenza and influenza vaccination can be useful in overcoming low compliance rates. The purpose of our study is to evaluate the opinion of HCW and students regarding influenza, influenza vaccine and the factors associated with vaccination compliance. A survey was conducted between October 2010 and April 2011 in the Florence metropolitan area. A questionnaire was administered to HCW in three local healthcare units and at Careggi University Teaching Hospital. Students matriculating in health degree programs at Florence University were also surveyed.
The coverage with vaccination against seasonal and pandemic influenza is generally low, and it is lower in students than in HCW (12.5% vs 15% for the seasonal vaccination, 8.5% vs 18% for the pandemic vaccination). Individuals comply with vaccination offer mainly to protect themselves and their contacts. Individuals not receiving vaccination did not consider themselves at risk, had never been vaccinated before or believed that pandemic influenza was not a public health concern. Physicians had the highest compliance to vaccination and women were less frequently vaccinated than men. HCW do not appear to perceive their possible influenza infections as a risk for patients: HCW receive vaccination mainly as a form of personal protection.
Low compliance to vaccination is determined by various factors and therefore requires a multi-faceted strategy of response. This should include short-term actions to overcome organizational barriers, in addition to long-term interventions to raise HCW’s level of knowledge about influenza and influenza vaccination.
doi:10.4161/hv.26036
PMCID: PMC4162047  PMID: 23954990
attitudes towards vaccine; vaccine policy; health care workers; influenza; H1N1; pandemic
6.  Barriers to Provider-Initiated Testing and Counselling for Children in a High HIV Prevalence Setting: A Mixed Methods Study 
PLoS Medicine  2014;11(5):e1001649.
Rashida Ferrand and colleagues combine quantitative and qualitative methods to investigate HIV prevalence among older children receiving primary care in Harare, Zimbabwe, and reasons why providers did not pursue testing.
Please see later in the article for the Editors' Summary
Background
There is a substantial burden of HIV infection among older children in sub-Saharan Africa, the majority of whom are diagnosed after presentation with advanced disease. We investigated the provision and uptake of provider-initiated HIV testing and counselling (PITC) among children in primary health care facilities, and explored health care worker (HCW) perspectives on providing HIV testing to children.
Methods and Findings
Children aged 6 to 15 y attending six primary care clinics in Harare, Zimbabwe, were offered PITC, with guardian consent and child assent. The reasons why testing did not occur in eligible children were recorded, and factors associated with HCWs offering and children/guardians refusing HIV testing were investigated using multivariable logistic regression. Semi-structured interviews were conducted with clinic nurses and counsellors to explore these factors. Among 2,831 eligible children, 2,151 (76%) were offered PITC, of whom 1,534 (54.2%) consented to HIV testing. The main reasons HCWs gave for not offering PITC were the perceived unsuitability of the accompanying guardian to provide consent for HIV testing on behalf of the child and lack of availability of staff or HIV testing kits. Children who were asymptomatic, older, or attending with a male or a younger guardian had significantly lower odds of being offered HIV testing. Male guardians were less likely to consent to their child being tested. 82 (5.3%) children tested HIV-positive, with 95% linking to care. Of the 940 guardians who tested with the child, 186 (19.8%) were HIV-positive.
Conclusions
The HIV prevalence among children tested was high, highlighting the need for PITC. For PITC to be successfully implemented, clear legislation about consent and guardianship needs to be developed, and structural issues addressed. HCWs require training on counselling children and guardians, particularly male guardians, who are less likely to engage with health care services. Increased awareness of the risk of HIV infection in asymptomatic older children is needed.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Over 3 million children globally are estimated to be living with HIV (the virus that causes AIDS). While HIV infection is most commonly spread through unprotected sex with an infected person, most HIV infections among children are the result of mother-to-child HIV transmission during pregnancy, delivery, or breastfeeding. Mother-to-child transmission can be prevented by administering antiretroviral therapy to mothers with HIV during pregnancy, delivery, and breast feeding, and to their newborn babies. According to a report by the Joint United Nations Programme on HIV/AIDS published in 2012, 92% of pregnant women with HIV were living in sub-Saharan Africa and just under 60% were receiving antiretroviral therapy. Consequently, sub-Saharan Africa is the region where most children infected with HIV live.
Why Was This Study Done?
If an opportunity to prevent mother-to-child transmission around the time of birth is missed, diagnosis of HIV infection in a child or adolescent is likely to depend on HIV testing in health care facilities. Health care provider–initiated HIV testing and counselling (PITC) for children is important in areas where HIV infection is common because earlier diagnosis allows children to benefit from care that can prevent the development of advanced HIV disease. Even if a child or adolescent appears to be in good health, access to care and antiretroviral therapy provides a health benefit to the individual over the long term. The administration of HIV testing (and counselling) to children relies not only on health care workers (HCWs) offering HIV testing but also on parents or guardians consenting for a child to be tested. However, more than 30% of children in countries with severe HIV epidemics are AIDS orphans, and economic conditions in these countries cause many adults to migrate for work, leaving children under the care of extended families. This study aimed to investigate the reasons for acceptance and rejection of PITC in primary health care settings in Harare, Zimbabwe. By exploring HCW perspectives on providing HIV testing to children and adolescents, the study also sought to gain insight into factors that could be hindering implementation of testing procedures.
What Did the Researchers Do and Find?
The researchers identified all children aged 6 to 15 years old at six primary care clinics in Harare, who were offered HIV testing as part of routine care between 22 January and 31 May 2013. Study fieldworkers collected data on numbers of child attendances, numbers offered testing, numbers who underwent HIV testing, and reasons why HIV testing did not occur. During the study 2,831 children attending the health clinics were eligible for PITC, and just over half (1,534, 54.2%) underwent HIV testing. Eighty-two children tested HIV-positive, and nearly all of them received counselling, medication, and follow-up care. HCWs offered the test to around 75% of those eligible. The most frequent explanation given by HCWs for a diagnostic test not being offered was that the child was accompanied by a guardian not appropriate for providing consent (401 occasions, 59%); Other reasons given were a lack of available counsellors or test kits and counsellors refusing to conduct the test. The likelihood of being offered the test was lower for children not exhibiting symptoms (such as persistent skin problems), older children, or those attending with a male or a younger guardian. In addition, over 100 guardians or parents provided consent but left before the child could be tested.
The researchers also conducted semi-structured interviews with 12 clinic nurses and counsellors (two from each clinic) to explore challenges to implementation of PITC. The researchers recorded the factors associated with testing not taking place, either when offered to eligible children or when HCWs declined to offer the test. The interviewees identified the frequent absence or unavailability of parents or legal guardians as an obstacle, and showed uncertainty or misconceptions around whether testing of the guardian was mandatory (versus recommended) and whether specifically a parent (if one was living) must provide consent. The interviews also revealed HCW concerns about the availability of adequate counselling and child services, and fears that a child might experience maltreatment if he or she tested positive. HCWs also noted long waiting times and test kits being out of stock as practical hindrances to testing.
What Do These Findings Mean?
Prevalence of HIV was high among the children tested, validating the need for PITC in sub-Saharan health care settings. Although 76% of eligible attendees were offered testing, the authors note that this is likely higher than in routine settings because the researchers were actively recording reasons for not offering testing and counselling, which may have encouraged heath care staff to offer PITC more often than usual. The researchers outline strategies that may improve PITC rates and testing acceptance for Zimbabwe and other sub-Saharan settings. These strategies include developing clear laws and guidance concerning guardianship and proxy consent when testing older children for HIV, training HCWs around these policies, strengthening legislation to address discrimination, and increasing public awareness about HIV infection in older children.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001649.
This study is further discussed in a PLOS Medicine Perspective by Davies and Kalk
The Joint United Nations Programme on HIV/AIDS publishes an annual report on the global AIDS epidemic, which provides information on progress towards eliminating new HIV infections
The World Health Organization has more information on mother-to-child transmission of HIV
The World Health Organization's website also has information about treatment for children living with HIV
Personal stories about living with HIV/AIDS, including stories from young people infected with HIV, are available through Avert, through NAM/aidsmap, and through the charity website Healthtalkonline
doi:10.1371/journal.pmed.1001649
PMCID: PMC4035250  PMID: 24866209
7.  Association between the 2008–09 Seasonal Influenza Vaccine and Pandemic H1N1 Illness during Spring–Summer 2009: Four Observational Studies from Canada 
PLoS Medicine  2010;7(4):e1000258.
In three case-control studies and a household transmission cohort, Danuta Skowronski and colleagues find an association between prior seasonal flu vaccination and increased risk of 2009 pandemic H1N1 flu.
Background
In late spring 2009, concern was raised in Canada that prior vaccination with the 2008–09 trivalent inactivated influenza vaccine (TIV) was associated with increased risk of pandemic influenza A (H1N1) (pH1N1) illness. Several epidemiologic investigations were conducted through the summer to assess this putative association.
Methods and Findings
Studies included: (1) test-negative case-control design based on Canada's sentinel vaccine effectiveness monitoring system in British Columbia, Alberta, Ontario, and Quebec; (2) conventional case-control design using population controls in Quebec; (3) test-negative case-control design in Ontario; and (4) prospective household transmission (cohort) study in Quebec. Logistic regression was used to estimate odds ratios for TIV effect on community- or hospital-based laboratory-confirmed seasonal or pH1N1 influenza cases compared to controls with restriction, stratification, and adjustment for covariates including combinations of age, sex, comorbidity, timeliness of medical visit, prior physician visits, and/or health care worker (HCW) status. For the prospective study risk ratios were computed. Based on the sentinel study of 672 cases and 857 controls, 2008–09 TIV was associated with statistically significant protection against seasonal influenza (odds ratio 0.44, 95% CI 0.33–0.59). In contrast, estimates from the sentinel and three other observational studies, involving a total of 1,226 laboratory-confirmed pH1N1 cases and 1,505 controls, indicated that prior receipt of 2008–09 TIV was associated with increased risk of medically attended pH1N1 illness during the spring–summer 2009, with estimated risk or odds ratios ranging from 1.4 to 2.5. Risk of pH1N1 hospitalization was not further increased among vaccinated people when comparing hospitalized to community cases.
Conclusions
Prior receipt of 2008–09 TIV was associated with increased risk of medically attended pH1N1 illness during the spring–summer 2009 in Canada. The occurrence of bias (selection, information) or confounding cannot be ruled out. Further experimental and epidemiological assessment is warranted. Possible biological mechanisms and immunoepidemiologic implications are considered.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Every winter, millions of people catch influenza—a viral infection of the airways—and hundreds of thousands of people die as a result. These seasonal epidemics occur because small but frequent changes in the influenza virus mean that an immune response produced one year through infection or vaccination provides only partial protection against influenza the next year. Annual vaccination with killed influenza viruses of the major circulating strains can greatly reduce a person's risk of catching influenza. Consequently, many countries run seasonal influenza vaccination programs. In most of Canada, vaccination with a mixture of three inactivated viruses (a trivalent inactivated vaccine or TIV) is provided free to children aged 6–23 months, to elderly people, to people with long-term conditions that increase their risk of influenza-related complications, and those who provide care for them; in Ontario, free vaccination is offered to everyone older than 6 months.
In addition, influenza viruses occasionally emerge that are very different and to which human populations have virtually no immunity. These viruses can start global epidemics (pandemics) that can kill millions of people. Experts have been warning for some time that an influenza pandemic is long overdue and, in March 2009, the first cases of influenza caused by a new virus called pandemic A/H1N1 2009 (pH1N1; swine flu) occurred in Mexico. The virus spread rapidly and on 11 June 2009, the World Health Organization declared that a global pandemic of pH1N1 influenza was underway. By the end of February 2010, more than 16,000 people around the world had died from pH1N1.
Why Was This Study Done?
During an investigation of a school outbreak of pH1N1 in the late spring 2009 in Canada, investigators noted that people with illness characterized by fever and coughing had been vaccinated against seasonal influenza more often than individuals without such illness. To assess whether this association between prior vaccination with seasonal 2008–09 TIV and subsequent pH1N1 illness was evident in other settings, researchers in Canada therefore conducted additional studies using different methods. In this paper, the researchers report the results of four additional studies conducted in Canada during the summer of 2009 to assess this possible association.
What Did the Researchers Do and Find?
The researchers conducted four epidemiologic studies. Epidemiology is the study of the causes, distribution, and control of diseases in populations.
Three of the four studies were case-control studies in which the researchers assessed the frequency of prior vaccination with the 2008–09 TIV in people with pH1N1 influenza compared to the frequency among healthy members of the general population or among individuals who had an influenza-like illness but no sign of infection with an influenza virus. The researchers also did a household transmission study in which they collected information about vaccination with TIV among the additional cases of influenza that were identified in 47 households in which a case of laboratory-confirmed pH1N1 influenza had occurred. The first of the case-control studies, which was based on Canada's vaccine effectiveness monitoring system, showed that, as expected, the 2008–09 TIV provided protection against seasonal influenza. However, estimates from all four studies (which included about 1,200 laboratory-confirmed pH1N1 cases and 1,500 controls) showed that prior recipients of the 2008–09 TIV had approximately 1.4–2.5 times increased chances of developing pH1N1 illness that needed medical attention during the spring–summer of 2009 compared to people who had not received the TIV. Prior seasonal vaccination was not associated with an increase in the severity of pH1N1 illness, however. That is, it did not increase the risk of being hospitalized among those with pH1N1 illness.
What Do These Findings Mean?
Because all the investigations in this study are “observational,” the people who had been vaccinated might share another unknown characteristic that is actually responsible for increasing their risk of developing pH1N1 illness (“confounding”). Furthermore, the results reported in this study might have arisen by chance, although the consistency of results across the studies makes this unlikely. Thus, the finding of an association between prior receipt of 2008–09 TIV and an increased risk of pH1N1 illness is not conclusive and needs to be investigated further, particularly since some other observational studies conducted in other countries have reported that seasonal vaccination had no influence or may have been associated with reduced chances of pH1N1 illness. If the findings in the current study are real, however, they raise important questions about the biological interactions between seasonal and pandemic influenza strains and vaccines, and about the best way to prevent and control both types of influenza in future.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/ 10.1371/journal.pmed.1000258.
This article is further discussed in a PLoS Medicine Perspective by Cécile Viboud and Lone Simonsen
FightFlu.ca, a Canadian government Web site, provides access to information on pH1N1 influenza
The US Centers for Disease Control and Prevention provides information about influenza for patients and professionals, including specific information on H1N1 influenza
Flu.gov, a US government website, provides access to information on H1N1, avian and pandemic influenza
The World Health Organization provides information on seasonal influenza and has detailed information on pH1N1 influenza (in several languages)
The UK Health Protection Agency provides information on pandemic influenza and on pH1N1 influenza
doi:10.1371/journal.pmed.1000258
PMCID: PMC2850386  PMID: 20386731
8.  Longitudinal seroepidemiologic study of the 2009 pandemic influenza A (H1N1) infection among health care workers in a children's hospital 
Background
To probe seroepidemiology of the 2009 pandemic influenza A (H1N1) among health care workers (HCWs) in a children's hospital.
Methods
From August 2009 to March 2010, serum samples were drawn from 150 HCWs in a children's hospital in Taipei before the 2009 influenza A (H1N1) pandemic, before H1N1 vaccination, and after the pandemic. HCWs who had come into direct contact with 2009 influenza A (H1N1) patients or their clinical respiratory samples during their daily work were designated as a high-risk group. Antibody levels were determined by hemagglutination inhibition (HAI) assay. A four-fold or greater increase in HAI titers between any successive paired sera was defined as seroconversion, and factors associated with seroconversion were analyzed.
Results
Among the 150 HCWs, 18 (12.0%) showed either virological or serological evidence of 2009 pandemic influenza A (H1N1) infection. Of the 90 unvaccinated HCWs, baseline and post-pandemic seroprotective rates were 5.6% and 20.0%. Seroconversion rates among unvaccinated HCWs were 14.4% (13/90), 22.5% (9/40), and 8.0% (4/50) for total, high-risk group, and low-risk group, respectively. Multivariate analysis revealed being in the high-risk group is an independent risk factor associated with seroconversion.
Conclusion
The infection rate of 2009 pandemic influenza A (H1N1) in HCWs was moderate and not higher than that for the general population. The majority of unvaccinated HCWs remained susceptible. Direct contact of influenza patients and their respiratory samples increased the risk of infection.
doi:10.1186/1471-2334-12-89
PMCID: PMC3364885  PMID: 22498010
Influenza; Pandemic; H1N1; Health care workers; Children
9.  Acceptance of a Vaccine Against Novel Influenza A (H1N1) Virus Among Health Care Workers in Two Major Cities in Mexico 
Archives of medical research  2009;40(8):705-711.
Background and Aims
Further cases of novel influenza A (H1N1) outbreak are expected in the coming months. Vaccination has been proven to be essential to control a pandemic of influenza; therefore, considerable efforts and resources have been devoted to develop a vaccine against the influenza A (H1N1) virus. With the current availability of the vaccine, it will be important to immunize as many people as possible. However, previous data with seasonal influenza vaccines have shown that there are multiple barriers related to perceptions and attitudes of the population that influence vaccine use. The aim of the study was to evaluate the acceptance of a newly developed vaccine against pandemic (H1N1) 2009 influenza A among healthcare workers (HCW) in Mexico.
Methods
We conducted a cross-sectional study among HCW in three hospitals in the two largest cities in Mexico—Mexico City and Guadalajara—between June and September 2009.
Results
A total of 1097 HCW participated in the survey. Overall, 80% (n = 880) intended to accept the H1N1 pandemic vaccine and 71.6% (n = 786) reported they would recommend the vaccine to their patients. Doctors were more likely to accept and recommend the vaccine than nurses. HCWs who intend to be immunized will be more likely to do so if they know that the vaccine is safe and effective.
Conclusions
Knowledge of the willingness to accept the vaccine can be used to plan strategies that will effectively respond to the needs of the population studied, reducing the health and economic impact of novel influenza A (H1N1) virus.
doi:10.1016/j.arcmed.2010.01.004
PMCID: PMC2854164  PMID: 20304260
Vaccine acceptance; Influenza A (H1N1) virus; Health care workers
10.  Getting vaccinated or not getting vaccinated? Different reasons for getting vaccinated against seasonal or pandemic influenza 
BMC Public Health  2013;13:1221.
Background
A large number of studies have investigated the motivation behind health care workers (HCWs) taking the influenza vaccine. But with the appearance of pandemic influenza, it became important to better analyse the reasons why workers get vaccinated against seasonal and/or pandemic influenza.
Methods
Three main categories of reasons were identified with an Exploratory Factor Analysis. An analysis of variance (ANOVA) was used to verify the existence of differences between three categories of choices (taking of seasonal and pandemic vaccine, only the seasonal vaccine or none). In addition, a multinomial logistic regression analysis was performed to analyse the association between stated intentions and update of seasonal and pandemic vaccine. Questionnaires were returned from 168 HCWs (67.3% women).
Results
The results showed that age and being well-informed about vaccination topics are the most important variables in determining the choice to take the vaccine.
Conclusions
The results highlight the importance of enhancing education programs to improve awareness among HCWs concerning the benefits of taking the influenza vaccination, with particular attention paid to younger workers.
doi:10.1186/1471-2458-13-1221
PMCID: PMC4029192  PMID: 24359091
Vaccine; Pandemic influenza; Seasonal influenza; HCWs
11.  Protecting patients, protecting healthcare workers: a review of the role of influenza vaccination 
International Nursing Review  2011;59(2):161-167.
MUSIC T. (2012) A review of the role the role of influenza vaccination in protecting patients, protecting healthcare workers the role of influenza vaccination. International Nursing Review59, 161–167
Aim:
Many health authorities recommend routine influenza vaccination for healthcare workers (HCWs), and during the 2009 A (H1N1) pandemic, the World Health Organization (WHO) recommended immunization of all HCWs worldwide. As this remains an important area of policy debate, this paper examines the case for vaccination, the role of local guidelines, barriers to immunization and initiatives to increase uptake.
Background:
Seasonal influenza is a major threat to public health, causing up to 1 million deaths annually. Extensive evidence supports the vaccination of priority groups, including HCWs. Immunization protects HCWs themselves, and their vulnerable patients from nosocomial influenza infections. In addition, influenza can disrupt health services and impact healthcare organizations financially. Immunization can reduce staff absences, offer cost savings and provide economic benefits.
Methods:
This paper reviews official immunization recommendations and HCW vaccination studies, including a recent International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) survey of 26 countries from each region of the world.
Results:
HCW immunization is widely recommended and supported by the WHO. In the IFPMA study, 88% of countries recommended HCW vaccination, and 61% supported this financially (with no correlation to country development status). Overall, coverage can be improved, and research shows that uptake may be impacted by lack of conveniently available vaccines and misconceptions regarding vaccine safety/efficacy and influenza risk.
Conclusions:
Many countries recommend HCW vaccination against influenza. In recent years, there has been an increased uptake rate among HCWs in some countries, but not in others. Several initiatives can increase coverage, including education, easy access to free vaccines and the use of formal declination forms. The case for HCW vaccination is clear, and in an effort to further accelerate uptake as a patient safety measure, an increasing number of healthcare organizations, particularly in the USA, are implementing mandatory immunization policies, similar to other obligatory hygiene measures. However, it would be desirable if similar high vaccination uptake rates could be achieved through voluntary procedures.
doi:10.1111/j.1466-7657.2011.00961.x
PMCID: PMC3418836  PMID: 22591085
Coverage; Education; Guideline; Influenza; Policy; Recommendation; Reimbursement; Seasonal; Vaccine
12.  BRIEF REPORT: Influenza Vaccination and Health Care Workers in the United States 
OBJECTIVE
To determine influenza vaccination rates among U.S. health care workers (HCWs) by demographic and occupational categories.
DESIGN AND PARTICIPANTS
We analyzed data from the 2000 National Health Interview Survey (NHIS). Weighted multivariable analyses were used to evaluate the association between HCW occupation and other variables potentially related to receipt of influenza vaccination. HCWs were categorized based on standard occupational classifications as health-diagnosing professions, health-assessing professions, health aides, health technicians; or health administrators.
MAIN INDEPENDENT VARIABLES
Demographic characteristics and occupation category.
MAIN OUTCOME VARIABLES
Receipt of influenza vaccination within 12 months of survey.
ANALYSIS
Descriptive statistics and weighted multivariable logistic regression.
RESULTS
There were 1,651 HCWs in the final sample. The overall influenza vaccination rate for HCWs was 38%. After weighted multivariable analyses, HCWs who were under 50 (odds ratio [OR] 0.67%, 95% confidence interval [CI]: 0.50 to 0.89, compared with HCWs 50 to 64), black (OR 0.57 95% CI: 0.42, 0.78, compared with white HCWs), or were health aides (OR 0.73%, 95% CI: 0.51, 1.04, compared with health care administrators and administrative support staff) had lower odds of having been vaccinated against influenza.
CONCLUSIONS
The overall influenza vaccination rate among HCWs in the United States is low. Workers who are under 50, black, or health aides have the lowest rates of vaccinations. Interventions seeking to improve HCW vaccination rates may need to target these specific subgroups.
doi:10.1111/j.1525-1497.2006.00325.x
PMCID: PMC1484661  PMID: 16606378
Influenza vaccinations; health care workers; National Health Interview Survey; nosocomial infection; employee health
13.  Personal Decision-Making Criteria Related to Seasonal and Pandemic A(H1N1) Influenza-Vaccination Acceptance among French Healthcare Workers 
PLoS ONE  2012;7(7):e38646.
Background
Influenza-vaccination rates among healthcare workers (HCW) remain low worldwide, even during the 2009 A(H1N1) pandemic. In France, this vaccination is free but administered on a voluntary basis. We investigated the factors influencing HCW influenza vaccination.
Methods
In June–July 2010, HCW from wards of five French hospitals completed a cross-sectional survey. A multifaceted campaign aimed at improving vaccination coverage in this hospital group was conducted before and during the 2009 pandemic. Using an anonymous self-administered questionnaire, we assessed the relationships between seasonal (SIV) and pandemic (PIV) influenza vaccinations, and sociodemographic and professional characteristics, previous and current vaccination statuses, and 33 statements investigating 10 sociocognitive domains. The sociocognitive domains describing HCWs' SIV and PIV profiles were analyzed using the classification-and-regression–tree method.
Results
Of the HCWs responding to our survey, 1480 were paramedical and 401 were medical with 2009 vaccination rates of 30% and 58% for SIV and 21% and 71% for PIV, respectively (p<0.0001 for both SIV and PIV vaccinations). Older age, prior SIV, working in emergency departments or intensive care units, being a medical HCW and the hospital they worked in were associated with both vaccinations; while work shift was associated only with PIV. Sociocognitive domains associated with both vaccinations were self-perception of benefits and health motivation for all HCW. For medical HCW, being a role model was an additional domain associated with SIV and PIV.
Conclusions
Both vaccination rates remained low. Vaccination mainly depended on self-determined factors and for medical HCW, being a role model.
doi:10.1371/journal.pone.0038646
PMCID: PMC3407215  PMID: 22848342
14.  Long-Term Immunogenicity of the Pandemic Influenza A/H1N1 2009 Vaccine among Health Care Workers: Influence of Prior Seasonal Influenza Vaccination 
Health care workers (HCWs) are at great risk of influenza infection and transmission. Vaccination for seasonal influenza is routinely recommended, but this strategy should be reconsidered in a pandemic situation. Between October 2009 and September 2010, a multicenter study was conducted to assess the long-term immunogenicity of the A/H1N1 2009 monovalent influenza vaccine among HCWs compared to non-health care workers (NHCWs). The influence of prior seasonal influenza vaccination was also assessed with respect to the immunogenicity of pandemic H1N1 influenza vaccine. Serum hemagglutinin inhibition titers were determined prevaccination and then at 1, 6, and 10 months after vaccination. Of the 360 enrolled HCW subjects, 289 participated in the study up to 10 months after H1N1 monovalent influenza vaccination, while 60 of 65 NHCW subjects were followed up. Seroprotection rates, seroconversion rates, and geometric mean titer (GMT) ratios fulfilled the European Union's licensure criteria for influenza A/California/7/2009 (H1N1) at 1 month after vaccination in both the HCWs and NHCWs, without any significant difference. At 6 months after vaccination, the seroprotection rate was more significantly lowered among the NHCWs than among the HCWs (P < 0.01). Overall, postvaccination (1, 6, and 10 months after vaccination) GMTs for A/California/7/2009 (H1N1) were significantly lower among the seasonal influenza vaccine recipients than among the nonrecipients (P < 0.05). In conclusion, HCWs should be encouraged to receive an annual influenza vaccination, considering the risk of repeated exposure. However, prior reception of seasonal influenza vaccine showed a negative influence on immunogenicity for the pandemic A/H1N1 2009 influenza vaccine.
doi:10.1128/CVI.00725-12
PMCID: PMC3623406  PMID: 23365206
15.  Barriers to pandemic influenza vaccination and uptake of seasonal influenza vaccine in the post-pandemic season in Germany 
BMC Public Health  2012;12:938.
Background
In Germany, annual vaccination against seasonal influenza is recommended for certain target groups (e.g. persons aged ≥60 years, chronically ill persons, healthcare workers (HCW)). In season 2009/10, vaccination against pandemic influenza A(H1N1)pdm09, which was controversially discussed in the public, was recommended for the whole population. The objectives of this study were to assess vaccination coverage for seasonal (seasons 2008/09-2010/11) and pandemic influenza (season 2009/10), to identify predictors of and barriers to pandemic vaccine uptake and whether the controversial discussions on pandemic vaccination has had a negative impact on seasonal influenza vaccine uptake in Germany.
Methods
We analysed data from the ‘German Health Update’ (GEDA10) telephone survey (n=22,050) and a smaller GEDA10-follow-up survey (n=2,493), which were both representative of the general population aged ≥18 years living in Germany.
Results
Overall only 8.8% of the adult population in Germany received a vaccination against pandemic influenza. High socioeconomic status, having received a seasonal influenza shot in the previous season, and belonging to a target group for seasonal influenza vaccination were independently associated with the uptake of pandemic vaccines. The main reasons for not receiving a pandemic vaccination were ‘fear of side effects’ and the opinion that ‘vaccination was not necessary’. Seasonal influenza vaccine uptake in the pre-pandemic season 2008/09 was 52.8% among persons aged ≥60 years; 30.5% among HCW, and 43.3% among chronically ill persons. A decrease in vaccination coverage was observed across all target groups in the first post-pandemic season 2010/11 (50.6%, 25.8%, and 41.0% vaccination coverage, respectively).
Conclusions
Seasonal influenza vaccination coverage in Germany remains in all target groups below 75%, which is a declared goal of the European Union. Our results suggest that controversial public discussions about safety and the benefits of pandemic influenza vaccination may have contributed to both a very low uptake of pandemic vaccines and a decreased uptake of seasonal influenza vaccines in the first post-pandemic season. In the upcoming years, the uptake of seasonal influenza vaccines should be carefully monitored in all target groups to identify if this trend continues and to guide public health authorities in developing more effective vaccination and communication strategies for seasonal influenza vaccination.
doi:10.1186/1471-2458-12-938
PMCID: PMC3527143  PMID: 23113995
Vaccination; Influenza; Coverage; Pandemic; Germany
16.  Short and Long-Term Safety of the 2009 AS03-Adjuvanted Pandemic Vaccine 
PLoS ONE  2012;7(7):e38563.
Background
This study assessed the short and the long term safety of the 2009 AS03 adjuvanted monovalent pandemic vaccine through an active web-based electronic surveillance. We compared its safety profile to that of the seasonal trivalent inactivated influenza vaccine (TIV) for 2010–2011.
Methodology/Principal Findings
Health care workers (HCW) vaccinated in 2009 with the pandemic vaccine (Arepanrix ® from GSK) or HCW vaccinated in 2010 with the 2010–2011 TIV were invited to participate in a web-based active surveillance of vaccine safety. They completed two surveys the day-8 survey covered the first 7 days post-vaccination and the day-29 survey covered events occurring 8 to 28 days after vaccination. Those who reported a problem were called by a nurse to obtain details. The main outcome was the occurrence of a new health problem or the worsening of an existing health condition that resulted in a medical consultation or work absenteeism. For the pandemic vaccine, a six-month follow-up for the occurrence of serious adverse events (SAE) was conducted. Among the 6242 HCW who received the pandemic vaccine, 440 (7%) reported 468 events compared to 328 of the 7645 HCW (4.3%) who reported 339 events after the seasonal vaccine. The 2009 pandemic vaccine was associated with significantly more local reactions than the 2010–2011 seasonal vaccine (1% vs. 0.03%, p<0.001). Paresthesia was reported by 7 HCW (0.1%) after the pandemic vaccine but by none after the seasonal vaccine. For the pandemic vaccine, no clustering of SAE was found in the 6 month follow-up.
Conclusion
The 2009 pandemic vaccine seems to have a good safety profile, similar to the 2010–2011 TIV, with the exception of local reactions. This surveillance was adequately powered to identify AE associated with an excess risk ≥1 per 1000 vaccinations but is insufficient to detect rare AE.
Trial Registration
ClinicalTrials.gov NCT01289418, NCT01318876
doi:10.1371/journal.pone.0038563
PMCID: PMC3389012  PMID: 22802929
17.  Planning and process evaluation of a multi-faceted influenza vaccination implementation strategy for health care workers in acute health care settings 
BMC Infectious Diseases  2013;13:235.
Background
Influenza transmitted by health care workers (HCWs) is a potential threat to frail patients in acute health care settings. Therefore, immunizing HCWs against influenza should receive high priority. Despite recommendations of the World Health Organization, vaccine coverage of HCWs remains low in all European countries. This study explores the use of intervention strategies and methods to improve influenza vaccination rates among HCWs in an acute care setting.
Methods
The Intervention Mapping (IM) method was used to systematically develop and implement an intervention strategy aimed at changing influenza vaccination behaviour among HCWs in Dutch University Medical Centres (UMCs). Carried out during the influenza seasons 2009/2010 and 2010/2011, the interventions were then qualitatively and quantitatively evaluated by way of feedback from participating UMCs and the completion of a web-based staff questionnaire in the following spring of each season.
Results
The IM method resulted in the development of a transparent influenza vaccination intervention implementation strategy. The intervention strategy was offered to six Dutch UMCs in a randomized in a clustered Randomized Controlled Trial (RCT), where three UMCs were chosen for intervention, and three UMCs acted as controls. A further two UMCs elected to have the intervention. The qualitative process evaluation showed that HCWs at four of the five intervention UMCs were responsive to the majority of the 11 relevant behavioural determinants resulting from the needs assessment in their intervention strategy compared with only one of three control UMCs. The quantitative evaluation among a sample of HCWs revealed that of all the developed communication materials, HCWs reported the posters as the most noticeable.
Conclusions
Our study demonstrates that it is possible to develop a structured implementation strategy for increasing the rate of influenza vaccination by HCWs in acute health care settings. The evaluation also showed that it is impossible to expose all HCWs to all intervention methods (which would have been the best case scenario). Further study is needed to (1) improve HCW exposure to intervention methods; (2) determine the effect of such interventions on vaccine uptake among HCWs; and (3) assess the impact on clinical outcomes among patients when such interventions are enacted.
doi:10.1186/1471-2334-13-235
PMCID: PMC3680164  PMID: 23701921
Influenza vaccination; Health care workers; Intervention mapping; Intervention implementation; Acute health care
18.  Determinants of influenza vaccination uptake among Italian healthcare workers 
We analyzed seasonal influenza vaccination coverage among the Italian healthcare workers (HCW) in order to identify socio-demographic and clinical determinants of vaccination.
We used data from the survey “Health and health care use in Italy,” which comprised interviews of 5,336 HCWs For each respondent, information on socioeconomic, health conditions, self-perceived health and smoking status were obtained. After bivariate analysis, we used multilevel regression models to assess determinants of immunization. Overall 20.8% of HCWs (95%CI 19.7–21.9) reported being vaccinated against seasonal influenza.
After controlling for potential confounders, multilevel regression revealed that older workers have a higher likelihood of vaccine uptake (OR = 6.07; 95% CI 4.72–7.79). Conversely, higher education was associated with lower vaccine uptake (OR = 0.65; 95% IC 0.50–0.83). Those suffering from diabetes (OR = 2.07; 95% CI 1.19–1.69), COPD (OR = 1.95; 95% CI 1.31–2.89) and cardiovascular diseases (OR = 1.48 95% CI 1.11–1.96) were more likely to be vaccinated. Likewise, smokers, or former smokers receive more frequently the vaccination (OR = 1.40; 95% CI 1.15–1.70; OR = 1.54; 95% CI 1.24–1.91, respectively) compared with never-smokers as well as those HCWs reporting fair or poor perceived health status (ORs of 1.68, 95% CI 1.30–2.18).
Vaccine coverage among HCWs in Italy remains low, especially among those with no comorbidities and being younger than 44 y old. This behavior not only raises questions regarding healthcare organization, infection control in healthcare settings and clinical costs, but also brings up ethical issues concerning physicians who seem not to be very concerned about the impact of the flu on themselves, as well as on their patients. Influenza vaccination campaigns will only be effective if HCWs understand their role in influenza transmission and prevention, and realize the importance of vaccination as a preventive measure
doi:10.4161/hv.22997
PMCID: PMC3903913  PMID: 24064543
administration and dosage; attitude of health personnel; health behavior; human prevention and control; influenza; influenza vaccines; socioeconomic factors
19.  Prioritization strategies for pandemic influenza vaccine in 27 countries of the European Union and the Global Health Security Action Group: a review 
BMC Public Health  2007;7:236.
Background
Although there is rapid progress in vaccine research regarding influenza pandemic vaccines it is expected that pandemic influenza vaccine production can only start once the pandemic virus has been recognized. Therefore, pandemic vaccine capacity will be limited at least during the first phase of an influenza pandemic, requiring vaccine prioritization strategies. WHO recommends developing preliminary priorities for pandemic vaccine use. The goal of this review is to provide a thorough overview of pandemic vaccine prioritization concepts in the 27 European Union (EU) member states and the four non-EU countries of the Global Health Security Action Group.
Methods
Between September and December 2006 data was collected for each country through two data sources: (i) the national influenza pandemic plan; (ii) contacting key persons involved in pandemic planning by email and/or phone and/or fax
Results
Twenty-six (84%) countries had established at least one vaccine priority group. Most common reported vaccine priority groups were health care workers (HCW) (100%), essential service providers (ESP) (92%) and high risk individuals (HRI) (92%). Ranking of at least one vaccine priority group was done by 17 (65%) of 26 countries. Fifteen (88%) of these 17 countries including a ranking strategy, decided that HCW with close contact to influenza patients should be vaccinated first; in most countries followed and/or ranked equally by ESP and subsequently HRI. Rationales for prioritization were provided by 22 (85%) of 26 countries that established vaccine priority groups. There was large variation in the phrasing and level of detailed specification of rationales. Seven (32%) of 22 countries providing rationales clearly associated each vaccine priority group with the specific rationale. Ten (32% of the 31 countries studied) countries have consulted and involved ethical experts to guide decisions related to vaccine prioritization.
Conclusion
In the majority of the countries the establishment of vaccine priority groups, ranking and underlying rationales are in line with WHO recommendations. In most public plans the criteria by which prioritized groups are identified are not easily recognizable. Clarity however, may be necessary to assure public acceptability of the prioritization. Ethical experts, results of modelling exercises could play an increasing role in the future decision making process.
doi:10.1186/1471-2458-7-236
PMCID: PMC2048949  PMID: 17825095
20.  Knowledge, attitudes and anxiety towards influenza A/H1N1 vaccination of healthcare workers in Turkey 
BMC Infectious Diseases  2010;10:281.
Background
This study aimed to analyze the factors associated with knowledge and attitudes about influenza A (H1N1) and vaccination, and possible relations of these factors with anxiety among healthcare workers (HCW).
Methods
The study used a cross-sectional descriptive design, and it was carried out between 23 November and 4 December 2009. A total of 300 HCW from two hospitals completed a questionnaire. Data collection tools comprised a questionnaire and the State-Trait Anxiety Inventory (STAI).
Results
Vaccination rate for 2009 pandemic influenza A(H1N1) among HCW was low (12.7%). Most of the respondents believed the vaccine was not safe and protective. Vaccination refusal was mostly related to the vaccine's side effects, disbelief to vaccine's protectiveness, negative news about the vaccine and the perceived negative attitude of the Prime Minister to the vaccine. State anxiety was found to be high in respondents who felt the vaccine was unsafe.
Conclusions
HCW considered the seriousness of the outbreak, their vaccination rate was low. In vaccination campaigns, governments have to aim at providing trust, and media campaigns should be used to reinforce this trust as well. Accurate reporting by the media of the safety and efficacy of influenza vaccines and the importance of vaccines for the public health would likely have a positive influence on vaccine uptake. Uncertain or negative reporting about the vaccine is detrimental to vaccination efforts.
doi:10.1186/1471-2334-10-281
PMCID: PMC3161359  PMID: 20863386
21.  A Population-Based Evaluation of a Publicly Funded, School-Based HPV Vaccine Program in British Columbia, Canada: Parental Factors Associated with HPV Vaccine Receipt 
PLoS Medicine  2010;7(5):e1000270.
Analysis of a telephone survey by Gina Ogilvie and colleagues identifies the parental factors associated with HPV vaccine uptake in a school-based program in Canada.
Background
Information on factors that influence parental decisions for actual human papillomavirus (HPV) vaccine receipt in publicly funded, school-based HPV vaccine programs for girls is limited. We report on the level of uptake of the first dose of the HPV vaccine, and determine parental factors associated with receipt of the HPV vaccine, in a publicly funded school-based HPV vaccine program in British Columbia, Canada.
Methods and Findings
All parents of girls enrolled in grade 6 during the academic year of September 2008–June 2009 in the province of British Columbia were eligible to participate. Eligible households identified through the provincial public health information system were randomly selected and those who consented completed a validated survey exploring factors associated with HPV vaccine uptake. Bivariate and multivariate analyses were conducted to calculate adjusted odds ratios to identify the factors that were associated with parents' decision to vaccinate their daughter(s) against HPV. 2,025 parents agreed to complete the survey, and 65.1% (95% confidence interval [CI] 63.1–67.1) of parents in the survey reported that their daughters received the first dose of the HPV vaccine. In the same school-based vaccine program, 88.4% (95% CI 87.1–89.7) consented to the hepatitis B vaccine, and 86.5% (95% CI 85.1–87.9) consented to the meningococcal C vaccine. The main reasons for having a daughter receive the HPV vaccine were the effectiveness of the vaccine (47.9%), advice from a physician (8.7%), and concerns about daughter's health (8.4%). The main reasons for not having a daughter receive the HPV vaccine were concerns about HPV vaccine safety (29.2%), preference to wait until the daughter is older (15.6%), and not enough information to make an informed decision (12.6%). In multivariate analysis, overall attitudes to vaccines, the impact of the HPV vaccine on sexual practices, and childhood vaccine history were predictive of parents having a daughter receive the HPV vaccine in a publicly funded school-based HPV vaccine program. By contrast, having a family with two parents, having three or more children, and having more education was associated with a decreased likelihood of having a daughter receive the HPV vaccine.
Conclusions
This study is, to our knowledge, one of the first population-based assessments of factors associated with HPV vaccine uptake in a publicly funded school-based program worldwide. Policy makers need to consider that even with the removal of financial and health care barriers, parents, who are key decision makers in the uptake of this vaccine, are still hesitant to have their daughters receive the HPV vaccine, and strategies to ensure optimal HPV vaccine uptake need to be employed.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
About 10% of cancers in women occur in the cervix, the structure that connects the womb to the vagina. Every year, globally, more than a quarter of a million women die because of cervical cancer, which only occurs after the cervix has been infected with a human papillomavirus (HPV) through sexual intercourse. There are many types of HPV, a virus that infects the skin and the mucosa (the moist membranes that line various parts of the body, including the cervix). Although most people become infected with HPV at some time in their life, most never know they are infected. However, some HPV types cause harmless warts on the skin or around the genital area and several—in particular, HPV 16 and HPV 18, so-called high-risk HPVs—can cause cervical cancer. HPV infections are usually cleared by the immune system, but about 10% of women infected with a high-risk HPV develop a long-term infection that puts them at risk of developing cervical cancer.
Why Was This Study Done?
Screening programs have greatly reduced cervical cancer deaths in developed countries in recent decades by detecting the cancer early when it can be treated; but it would be better to prevent cervical cancer ever developing. Because HPV is necessary for the development of cervical cancer, vaccination of girls against HPV infection before the onset of sexual activity might be one way to do this. Scientists recently developed a vaccine that prevents infection with HPV 16 and HPV 18 (and with two HPVs that cause genital warts) and that should, therefore, reduce the incidence of cervical cancer. Publicly funded HPV vaccination programs are now planned or underway in several countries; but before girls can receive the HPV vaccine, parental consent is usually needed, so it is important to know what influences parental decisions about HPV vaccination. In this study, the researchers undertake a telephone survey to determine the uptake of the HPV vaccine by 11-year-old girls (grade 6) in British Columbia, Canada, and to determine the parental factors associated with vaccine uptake; British Columbia started a voluntary school-based HPV vaccine program in September 2008.
What Did the Researchers Do and Find?
In early 2009, the researchers contacted randomly selected parents of girls enrolled in grade 6 during the 2008–2009 academic year and asked them to complete a telephone survey that explored factors associated with HPV vaccine uptake. 65.1% of the 2,025 parents who completed the survey had consented to their daughter receiving the first dose of HPV vaccine. By contrast, more than 85% of the parents had consented to hepatitis B and meningitis C vaccination of their daughters. Nearly half of the parents surveyed said their main reason for consenting to HPV vaccination was the effectiveness of the vaccine. Conversely, nearly a third of the parents said concern about the vaccine's safety was their main reason for not consenting to vaccination and one in eight said they had been given insufficient information to make an informed decision. In a statistical analysis of the survey data, the researchers found that a positive parental attitude towards vaccination, a parental belief that HPV vaccination had limited impact on sexual practices, and completed childhood vaccination increased the likelihood of a daughter receiving the HPV vaccine. Having a family with two parents or three or more children and having well-educated parents decreased the likelihood of a daughter receiving the vaccine.
What Do These Findings Mean?
These findings provide one of the first population-based assessments of the factors that affect HPV vaccine uptake in a setting where there are no financial or health care barriers to vaccination. By identifying the factors associated with parental reluctance to agree to HPV vaccination for their daughters, these findings should help public-health officials design strategies to ensure optimal HPV vaccine uptake, although further studies are needed to discover why, for example, parents with more education are less likely to agree to vaccination than parents with less education. Importantly, the findings of this study, which are likely to be generalizable to other high-income countries, indicate that there is a continued need to ensure that the public receives credible, clear information about both the benefits and long-term safety of HPV vaccination.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000270.
The US National Cancer Institute provides information about cervical cancer for patients and for health professionals, including information on HPV vaccines (in English and Spanish)
The US Centers for Disease Control and Prevention also has information about cervical cancer and about HPV
The UK National Health Service Choices website has pages on cervical cancer and on HPV vaccination
More information about cervical cancer and HPV vaccination is available from the Macmillan cancer charity
ImmunizeBC provides general information about vaccination and information about HPV vaccination in British Columbia
MedlinePlus provides links to additional resources about cervical cancer (in English and Spanish)
doi:10.1371/journal.pmed.1000270
PMCID: PMC2864299  PMID: 20454567
22.  Influenza Vaccination: Healthcare Workers Attitude in Three Middle East Countries 
Background: Healthcare workers (HCWs) pose a potential risk of transmitting communicable diseases in the hospital settings where they usually work. This study aims to determine the current influenza vaccination rates among HCWs in three Middle East countries namely United Arab Emirates (UAE), Kuwait and Oman, and also to identify the different variables associated with the noncompliance of HCWs to the recommendations of the Advisory Committee on Immunization Practices (ACIP) set in those countries. Methods: 1500 questionnaires were distributed to health care workers in the three countries during the period of July-October 2009. Results: Among 993 respondents, the vaccination rate was 24.7%, 67.2% and 46.4% in UAE, Kuwait and Oman, respectively. The different motivating factors that influenced the health care workers to take the vaccine was assessed and found that the most common factor that influenced their decision to take the vaccine was for their self protection (59%). On the other hand, the most common reason that discouraged HCWs to take the vaccine was “lack of time” as reported by 31.8% of the respondents. Other reasons for not taking the vaccine were unawareness of vaccine availability (29.4%), unavailability of vaccine (25.4%), doubts about vaccine efficacy (24.9%), lack of information about importance (20.1%) and concerns about its side effects (17.3%). Conclusions: influenza immunization by healthcare workers in the studied countries was suboptimal which could be improved by setting different interventions and educational programs to increase vaccination acceptance among HCWs.
PMCID: PMC2948215  PMID: 20922053
Influenza; healthcare workers; vaccination
23.  A Comparative Analysis of Influenza Vaccination Programs 
PLoS Medicine  2006;3(10):e387.
Background
The threat of avian influenza and the 2004–2005 influenza vaccine supply shortage in the United States have sparked a debate about optimal vaccination strategies to reduce the burden of morbidity and mortality caused by the influenza virus.
Methods and Findings
We present a comparative analysis of two classes of suggested vaccination strategies: mortality-based strategies that target high-risk populations and morbidity-based strategies that target high-prevalence populations. Applying the methods of contact network epidemiology to a model of disease transmission in a large urban population, we assume that vaccine supplies are limited and then evaluate the efficacy of these strategies across a wide range of viral transmission rates and for two different age-specific mortality distributions.
We find that the optimal strategy depends critically on the viral transmission level (reproductive rate) of the virus: morbidity-based strategies outperform mortality-based strategies for moderately transmissible strains, while the reverse is true for highly transmissible strains. These results hold for a range of mortality rates reported for prior influenza epidemics and pandemics. Furthermore, we show that vaccination delays and multiple introductions of disease into the community have a more detrimental impact on morbidity-based strategies than mortality-based strategies.
Conclusions
If public health officials have reasonable estimates of the viral transmission rate and the frequency of new introductions into the community prior to an outbreak, then these methods can guide the design of optimal vaccination priorities. When such information is unreliable or not available, as is often the case, this study recommends mortality-based vaccination priorities.
A comparative analysis of two classes of suggested vaccination strategies, mortality-based strategies that target high-risk populations and morbidity-based strategies that target high-prevalence populations.
Editors' Summary
Background.
Influenza—a viral infection of the nose, throat, and airways that is transmitted in airborne droplets released by coughing or sneezing—is a serious public health threat. Most people recover quickly from influenza, but some individuals, especially infants, old people, and individuals with chronic health problems, can develop pneumonia and die. In the US, seasonal outbreaks (epidemics) of flu cause an estimated 36,000 excess deaths annually. And now there are fears that avian influenza might start a human pandemic—a global epidemic that could kill millions. Seasonal outbreaks of influenza occur because flu viruses continually change the viral proteins (antigens) to which the immune system responds. “Antigenic drift”—small changes in these proteins—means that an immune system response that combats flu one year may not provide complete protection the next winter. “Antigenic shift”—large antigen changes—can cause pandemics because communities have no immunity to the changed virus. Annual vaccination with vaccines based on the currently circulating viruses controls seasonal flu epidemics; to control a pandemic, vaccines based on the antigenically altered virus would have to be quickly developed.
Why Was This Study Done?
Most countries target vaccination efforts towards the people most at risk of dying from influenza, and to health-care workers who are likely come into contact with flu patients. But is this the best way to reduce the burden of illness (morbidity) and death (mortality) caused by influenza, particularly at the start of a pandemic, when vaccine would be limited? Old people and infants are much less likely to catch and spread influenza than school children, students, and employed adults, so could vaccination of these sections of the population—instead of those most at risk of death—be the best way to contain influenza outbreaks? In this study, the researchers used an analytical method called “contact network epidemiology” to compare two types of vaccination strategies: the currently favored mortality-based strategy, which targets high-risk individuals, and a morbidity-based strategy, which targets those segments of the community in which most influenza cases occur.
What Did the Researchers Do and Find?
Most models of disease transmission assume that each member of a community is equally likely to infect every other member. But a baby is unlikely to transmit flu to, for example, an unrelated, housebound elderly person. Contact network epidemiology takes the likely relationships between people into account when modeling disease transmission. Using information from Vancouver, British Columbia, Canada, on household size, age distribution, and occupations, and other factors such as school sizes, the researchers built a model population of a quarter of a million interconnected people. They then investigated how different vaccination strategies controlled the spread of influenza in this population. The optimal strategy depended on the level of viral transmissibility—the likelihood that an infectious person transmits influenza to a susceptible individual with whom he or she has contact. For moderately transmissible flu viruses, a morbidity-based vaccination strategy, in which the people most likely to catch the flu are vaccinated, was more effective at containing seasonal and pandemic outbreaks than a mortality-based strategy, in which the people most likely to die if they caught the flu are vaccinated. For highly transmissible strains, this situation was reversed. The level of transmissibility at which this reversal occurred depended on several factors, including whether vaccination was delayed and how many times influenza was introduced into the community.
What Do These Findings Mean?
The researchers tested their models by checking that they could replicate real influenza epidemics and pandemics, but, as with all mathematical models, they included many assumptions about influenza in their calculations, which may affect their results. Also, because the contact network used data from Vancouver, their results might not be applicable to other cities, or to nonurban areas. Nevertheless, their findings have important public health implications. When there are reasonable estimates of the viral transmission rate, and it is known how often influenza is being introduced into a community, contact network models could help public health officials choose between morbidity- and mortality-based vaccination strategies. When the viral transmission rate is unreliable or unavailable (for example, at the start of a pandemic), the best policy would be the currently preferred strategy of mortality-based vaccination. More generally, the use of contact network models should improve estimates of how infectious diseases spread through populations and indicate the best ways to control human epidemics and pandemics.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0030387.
US Centers for Disease Control and Prevention information about influenza for patients and professionals, including key facts on vaccination
US National Institute of Allergy and Infectious Diseases feature on seasonal, avian, and pandemic influenza
World Health Organization fact sheet on influenza, with links to information on vaccination
UK Health Protection Agency information on seasonal, avian, and pandemic influenza
MedlinePlus entry on influenza
doi:10.1371/journal.pmed.0030387
PMCID: PMC1584413  PMID: 17020406
24.  Healthcare workers and health care-associated infections: knowledge, attitudes, and behavior in emergency departments in Italy 
Background
This survey assessed knowledge, attitudes, and compliance regarding standard precautions about health care-associated infections (HAIs) and the associated determinants among healthcare workers (HCWs) in emergency departments in Italy.
Methods
An anonymous questionnaire, self-administered by all HCWs in eight randomly selected non-academic acute general public hospitals, comprised questions on demographic and occupational characteristics; knowledge about the risks of acquiring and/or transmitting HAIs from/to a patient and standard precautions; attitudes toward guidelines and risk perceived of acquiring a HAI; practice of standard precautions; and sources of information.
Results
HCWs who know the risk of acquiring Hepatitis C (HCV) and Human Immunodeficiency Virus (HIV) from a patient were in practice from less years, worked fewer hours per week, knew that a HCW can transmit HCV and HIV to a patient, knew that HCV and HIV infections can be serious, and have received information from educational courses and scientific journals. Those who know that gloves, mask, protective eyewear, and hands hygiene after removing gloves are control measures were nurses, provided care to fewer patients, knew that HCWs' hands are vehicle for transmission of nosocomial pathogens, did not know that a HCW can transmit HCV and HIV to a patient, and have received information from educational courses and scientific journals. Being a nurse, knowing that HCWs' hands are vehicle for transmission of nosocomial pathogens, obtaining information from educational courses and scientific journals, and needing information were associated with a higher perceived risk of acquiring a HAI. HCWs who often or always used gloves and performed hands hygiene measures after removing gloves were nurses, provided care to fewer patients, and knew that hands hygiene after removing gloves was a control measure.
Conclusions
HCWs have high knowledge, positive attitudes, but low compliance concerning standard precautions. Nurses had higher knowledge, perceived risk, and appropriate HAIs' control measures than physicians and HCWs answered correctly and used appropriately control measures if have received information from educational courses and scientific journals.
doi:10.1186/1471-2334-10-35
PMCID: PMC2848042  PMID: 20178573
25.  Fighting Misconceptions to Improve Compliance with Influenza Vaccination among Health Care Workers: An Educational Project 
PLoS ONE  2012;7(2):e30670.
The compliance with influenza vaccination is poor among health care workers (HCWs) due to misconceptions about safety and effectiveness of influenza vaccine. We proposed an educational prospective study to demonstrate to HCWs that influenza vaccine is safe and that other respiratory viruses (RV) are the cause of respiratory symptoms in the months following influenza vaccination. 398 HCWs were surveyed for adverse events (AE) occurring within 48 h of vaccination. AE were reported by 30% of the HCWs. No severe AE was observed. A subset of 337 HCWs was followed up during four months, twice a week, for the detection of respiratory symptoms. RV was diagnosed by direct immunofluorescent assay (DFA) and real time PCR in symptomatic HCWs. Influenza A was detected in five episodes of respiratory symptoms (5.3%) and other RV in 26 (27.9%) episodes. The incidence density of influenza and other RV was 4.3 and 10.8 episodes per 100 HCW-month, respectively. The educational nature of the present study may persuade HCWs to develop a more positive attitude to influenza vaccination.
doi:10.1371/journal.pone.0030670
PMCID: PMC3273463  PMID: 22328920

Results 1-25 (1058636)