Theoretical models suggest that both HIV knowledge and HIV risk perception inform rational decision-making and, thus, predict safer sex motivation and behavior. However, the amount of variance explained by knowledge and risk perception is typically small. In this cross-sectional study, we investigated whether the predictive power of HIV knowledge and HIV risk perception on safer sex motivation is affected by trait anger. We hypothesized that anger may disrupt rational-decision making, distorting the effects of both HIV knowledge and risk perception on safer sex intentions. Data from 232 low-income, urban women at risk for HIV infection were used to test a path model with past sexual risk behavior, HIV knowledge, and HIV risk perception as predictors of safer sex intentions. Moderator effects of anger on safer sex intentions were tested by simultaneous group comparisons between high-anger and low-anger women (median-split). The theoretically expected “rational pattern” was found among low-anger women only, including (a) a positive effect of knowledge on safer sex intentions, and (b) buffer (inhibitor) effects of HIV knowledge and HIV risk perception on the negative path leading from past risk behavior to safer sex intentions. Among high-anger women, an “irrational pattern” emerged, with no effects of HIV knowledge and negative effects of both past risk behavior and HIV risk perception on safer sex intentions. In sum, the results suggest that rational knowledge and risk-based decisions regarding safer sex may be limited to low-anger women.
HIV; knowledge; anger; safer sex; intention; risk perception
The effectiveness of seasonal influenza vaccination programs depends on individual-level compliance. Perceptions about risks associated with infection and vaccination can strongly influence vaccination decisions and thus the ultimate course of an epidemic. Here we investigate the interplay between contact patterns, influenza-related behavior, and disease dynamics by incorporating game theory into network models. When individuals make decisions based on past epidemics, we find that individuals with many contacts vaccinate, whereas individuals with few contacts do not. However, the threshold number of contacts above which to vaccinate is highly dependent on the overall network structure of the population and has the potential to oscillate more wildly than has been observed empirically. When we increase the number of prior seasons that individuals recall when making vaccination decisions, behavior and thus disease dynamics become less variable. For some networks, we also find that higher flu transmission rates may, counterintuitively, lead to lower (vaccine-mediated) disease prevalence. Our work demonstrates that rich and complex dynamics can result from the interaction between infectious diseases, human contact patterns, and behavior.
When influenza spreads through a human population, its dynamics are shaped by both the complex patterns of contact that arise through our daily activities and individual decisions about the prevention and treatment of flu infections. However, until recently, mathematical models of flu transmission have ignored complex interaction and behavioral patterns in order to facilitate mathematical analyses. Here, we combine two recent approaches to modeling flu–network theory and game theory–to address the interplay between contact patterns and host vaccination decisions during seasonal flu outbreaks. Intuitively, the more contacts one has, the more likely he or she is to vaccinate. However, under the assumption that people make rational decisions based on complete information about the prior seasonal epidemic, vaccination decisions are predicted to vacillate dramatically. A severe epidemic in one year inspires high vaccination rates in the following year; this causes a milder epidemic which then leads to lower vaccination rates in the following year; and the cycle begins anew. We find further that the more homogeneous the contact patterns, the more pronounced the vacillations will be, and that decision-making based on multiple past seasons (rather than just one) leads to much more consistent behavior.
Vaccination against seasonal influenza is far from universal among groups specifically recommended for vaccine. There is little research to guide communication with patients about vaccination.
To assess the utility of the self-reported intention to be vaccinated against seasonal influenza in predicting vaccine uptake, reasons for being unvaccinated, and willingness to be vaccinated based on a doctor’s recommendation.
We analyzed data from a subset of respondents (n = 1,527) specifically recommended by the ACIP for vaccination against seasonal influenza who participated in two national surveys of adults age 18 and older conducted in November 2008 and March 2009.
Over half who intended to be vaccinated had been vaccinated. Compared to those without intentions, those with intentions were one-fifth as likely (p < 0.01) to cite lack of need and five times more likely (p < 0.01) to cite “not getting around to being vaccinated” as main reasons for not being vaccinated. Roughly two-fifths of those without the intention to be vaccinated indicated a willingness to be vaccinated based on a doctor’s recommendation.
Asking simple questions about the intention to be vaccinated against seasonal influenza may be an efficient means of identifying patients with whom extended discussion of vaccine benefits is warranted.
flu vaccination; self-reported intentions; study
Little research has been conducted to examine the influence of exposure to televised sexual content on adolescent sexuality or how parental intervention may reduce negative effects of viewing such content. This study uses self-report data from 1,012 adolescents to investigate the relations among exposure to sexually suggestive programming, parental mediation strategies, and three types of adolescent sexuality outcomes: participation in oral sex and sexual intercourse, future intentions to engage in these behaviors, and sex expectancies. As predicted, exposure to sexual content was associated with an increased likelihood of engaging in sexual behaviors, increased intentions to do so in the future, and more positive sex expectancies. Often, parental mediation strategies were a significant factor in moderating these potential media influences.
adolescent sexuality; media effects; parental mediation; sexual content; television exposure
During the course of an influenza pandemic, governments know relatively little about the possibly changing influence of government trust, risk perception, and receipt of information on the public's intention to adopt protective measures or on the acceptance of vaccination. This study aims to identify and describe possible changes in and factors associated with public's intentions during the 2009 influenza A (H1N1) pandemic in the Netherlands.
Sixteen cross-sectional telephone surveys were conducted (N = 8060) between April - November 2009. From these repeated measurements three consecutive periods were categorized based on crucial events during the influenza A (H1N1) pandemic. Time trends in government trust, risk perception, intention to adopt protective measures, and the acceptance of vaccination were analysed. Factors associated with an intention to adopt protective measures or vaccination were identified.
Trust in the government was high, but decreased over time. During the course of the pandemic, perceived vulnerability and an intention to adopt protective measures increased. Trust and vulnerability were associated with an intention to adopt protective measures in general only during period one. Higher levels of intention to receive vaccination were associated with increased government trust, fear/worry, and perceived vulnerability. In periods two and three receipt of information was positively associated with an intention to adopt protective measures. Most respondents wanted to receive information about infection prevention from municipal health services, health care providers, and the media.
The Dutch response to the H1N1 virus was relatively muted. Higher levels of trust in the government, fear/worry, and perceived vulnerability were all positively related to an intention to accept vaccination. Only fear/worry was positively linked to an intention to adopt protective measures during the entire pandemic. Risk and crisis communication by the government should focus on building and maintaining trust by providing information about preventing infection in close collaboration with municipal health services, health care providers, and the media.
The effectiveness of pandemic vaccine campaigns such as the H1N1 vaccine rollout is dependent on both the vaccines’ effectiveness and the general public’s willingness to be vaccinated. It is therefore critical to understand the factors that influence the decision of members of the public whether to get vaccinated with new, emergently released vaccines.
A systematic review of English language quantitative surveys was conducted to identify consistent predictors of the decision to accept or decline any (pre)pandemic vaccine, including the H1N1 influenza A vaccine. A total of ten studies were included in this review and all pertained to the 2009 H1N1 influenza A pandemic. Respondents’ willingness to receive a pandemic vaccine ranged from 8%–67% across the ten studies. The factors reported to be consistent predictors of the intention to vaccinate were: risk of infection, proximity or severity of the public health event, severity of personal consequences resulting from the illness, harm or adverse events from the vaccine, acceptance of previous vaccination, and ethnicity. Age and sex were the demographic variables examined most frequently across the ten studies and there was no consistent association between these variables and the intention to accept or reject a pandemic vaccine.
Some predictors of the intention to accept or decline a (pre)pandemic vaccine or the H1N1 influenza A vaccine are consistently identified by surveys. Understanding the important factors influencing the acceptance of a pandemic vaccine by individual members of the public may help inform strategies to improve vaccine uptake during future pandemics.
pandemic; H1N1 influenza A; emergent vaccine; personal risk; demographic
Vaccination is one of the cornerstones of controlling an influenza pandemic. To optimise vaccination rates in the general population, ways of identifying determinants that influence decisions to have or not to have a vaccination need to be understood. Therefore, this study aimed to predict intention to have a swine influenza vaccination in an adult population in the UK. An extension of the Theory of Planned Behaviour provided the theoretical framework for the study.
Three hundred and sixty two adults from the UK, who were not in vaccination priority groups, completed either an online (n = 306) or pen and paper (n = 56) questionnaire. Data were collected from 30th October 2009, just after swine flu vaccination became available in the UK, and concluded on 31st December 2009. The main outcome of interest was future swine flu vaccination intentions.
The extended Theory of Planned Behaviour predicted 60% of adults' intention to have a swine flu vaccination with attitude, subjective norm, perceived control, anticipating feelings of regret (the impact of missing a vaccination opportunity), intention to have a seasonal vaccine this year, one perceived barrier: "I cannot be bothered to get a swine flu vaccination" and two perceived benefits: "vaccination decreases my chance of getting swine flu or its complications" and "if I get vaccinated for swine flu, I will decrease the frequency of having to consult my doctor," being significant predictors of intention. Black British were less likely to intend to have a vaccination compared to Asian or White respondents.
Theoretical frameworks which identify determinants that influence decisions to have a pandemic influenza vaccination are useful. The implications of this research are discussed with a view to maximising any future pandemic influenza vaccination uptake using theoretically-driven applications.
The current study sought to determine knowledge about HPV, HPV vaccination and their relationship to cancer; assess acceptability of and intent to vaccinate; and describe the individual characteristics, cultural attitudes, social and environmental factors that affect African American parents' intent to vaccinate.
Two hundred African Americans completed self-administered surveys that assessed factors that may influence HPV vaccination behavior: HPV, cervical cancer, Pap and HPV vaccination knowledge; HPV and cervical cancer risk perception; cultural attitudes and beliefs, such as medical mistrust, spirituality/religiosity, and attitudes about adolescent sexuality and sexual risk behaviors. Eligibility criteria included men and women who: self-identified as African American and had a daughter nine to 17 years of age who had not been told that she had an HPV infection.
Among these African American parents, approximately two-thirds were aware of HPV and HPV vaccination. These individuals were likely to be female, younger, employed, to have social resources, and to have contact with family or friends previously diagnosed with cervical cancer. They were also knowledgeable about HPV, but knowledge did not necessarily lead to vaccination. Among the subgroup of aware individuals who reported having daughters that were and were not vaccinated, vaccination status was significantly affected by whether a pediatrician had recommended the vaccine (p < 0.001). A greater percentage of parents with vaccinated daughters were worried that their child would one day contract an STI. There were no significant differences between the vaccinated and non-vaccinated groups with respect to demographic characteristics or socio-cultural attitudes.
There is a need for continued HPV promotion and education efforts in the African American community. Discussions with pediatric and family practitioners are key to HPV education and promotion activities.
In June 2006, the first vaccine to prevent human papillomavirus (HPV) transmission was approved for use in females in the United States. Because the vaccine was approved for females as young as 9, its success depends on parents' and individuals' willingness to accept vaccination. Little is known about how attitudes toward this vaccine will be influenced by the way the vaccine is portrayed in the media or in public debate.
To assess the effects of information framing on intentions to vaccinate self or female children, if appropriate, 635 adults read one of three short descriptive paragraphs about the vaccine, each of which emphasized a different aspect of the vaccine. Participants were then asked about their intentions to vaccinate under cost or no-cost conditions.
Women who read that the vaccine protects only against cervical cancer had significantly higher intentions to vaccinate themselves when the vaccine was available at little or no cost compared with women who read alternate versions of the descriptive paragraph, F(2,325) = 5.74, p = 0.004.
How the HPV vaccine is framed may affect vaccination intentions under certain conditions. Women may be more receptive to the vaccine if it is framed as a cervical cancer prevention tool rather than a sexually transmitted infection (STI) prevention tool.
Comparative risk perceptions may rival other types of information in terms of effects on health behavior decisions.
We examined associations between comparative risk perceptions, affect, and behavior while controlling for absolute risk perceptions and actual risk.
Women at an increased risk of breast cancer participated in a program to learn about tamoxifen which can reduce the risk of breast cancer. Women reported comparative risk perceptions of breast cancer and completed measures of anxiety, knowledge, and tamoxifen-related behavior intentions. Three months later, women reported their behavior.
Comparative risk perceptions were positively correlated with anxiety, knowledge, intentions, and behavior three months later. After controlling for participants’ actual risk of breast cancer and absolute risk perceptions, comparative risk perceptions predicted anxiety and knowledge, but not intentions or behavior.
Comparative risk perceptions can affect patient outcomes like anxiety and knowledge independently of absolute risk perceptions and actual risk information.
comparative risk perception; breast cancer; behavioral decision-making; tamoxifen; decision aid
The influenza vaccination rate in hospitals among health care workers in Europe remains low. As there is a lack of research about management factors we assessed factors reported by administrators of general hospitals that are associated with the influenza vaccine uptake among health care workers.
All 81 general hospitals in the Netherlands were approached to participate in a self-administered questionnaire study. The questionnaire was directed at the hospital administrators. The following factors were addressed: beliefs about the effectiveness of the influenza vaccine, whether the hospital had a written policy on influenza vaccination and how the hospital informed their staff about influenza vaccination. The questionnaire also included questions about mandatory vaccination, whether it was free of charge and how delivered as well as the vaccination campaign costs. The outcome of this one-season survey is the self-reported overall influenza vaccination rate of health care workers.
In all, 79 of 81 hospitals that were approached were willing to participate and therefore received a questionnaire. Of these, 42 were returned (response rate 52%). Overall influenza vaccination rate among health care workers in our sample was 17.7% (95% confidence interval: 14.6% to 20.8%). Hospitals in which the administrators agreed with positive statements concerning the influenza vaccination had a slightly higher, but non-significant, vaccine uptake. There was a 9% higher vaccine uptake in hospitals that spent more than €1250,- on the vaccination campaign (24.0% versus 15.0%; 95% confidence interval from 0.7% to 17.3%).
Agreement with positive statements about management factors with regard to influenza vaccination were not associated with the uptake. More economic investments were related with a higher vaccine uptake; the reasons for this should be explored further.
Health care workers; Influenza vaccination; General hospital; Management
This study was carried out to estimate the vaccination coverage, public perception, and preventive behaviors against pandemic influenza A (H1N1) and to understand the motivation and barriers to vaccination between high-risk and non–high-risk groups during the outbreak of pandemic influenza A (H1N1).
A cross-sectional nationwide telephone survey of 1,650 community-dwelling Korean adults aged 19 years and older was conducted in the later stage of the 2009–2010 pandemic influenza A (H1N1) outbreak. The questionnaire identified the demographics, vaccination status of participants and all household members, barriers to non-vaccination, perceived threat, and preventive behaviors. In Korea, the overall rate of pandemic influenza vaccination coverage in the surveyed population was 15.5%; vaccination coverage in the high-risk group and non–high-risk group was 47.3% and 8.0%, respectively. In the high-risk group, the most important triggering event for vaccination was receiving a notice from a public health organization. In the non–high-risk group, vaccination was more strongly influenced by previous experience with influenza or mass media campaigns. In both groups, the most common reasons for not receiving vaccination was that their health was sufficient to forgo the vaccination, and lack of time. There was no significant difference in how either group perceived the threat or adopted preventive behavior. The predictive factors for pandemic influenza vaccination were being elderly (age ≥65 years), prior seasonal influenza vaccination, and chronic medical disease.
With the exception of vaccination coverage, the preventive behaviors of the high-risk group were not different from those of the non–high-risk group during the 2009–2010 pandemic. For future pandemic preparedness planning, it is crucial to reinforce preventive behaviors to avoid illness before vaccination and to increase vaccination coverage in the high-risk group.
Risk perception is a reported predictor of vaccination uptake, but which measures of risk perception best predict influenza vaccination uptake remain unclear.
During the main influenza seasons (between January and March) of 2009 (Wave 1) and 2010 (Wave 2),505 Chinese students and employees from a Hong Kong university completed an online survey. Multivariate logistic regression models were conducted to assess how well different risk perceptions measures in Wave 1 predicted vaccination uptake against seasonal influenza in Wave 2.
The results of the multivariate logistic regression models showed that feeling at risk (β = 0.25, p = 0.021) was the better predictor compared with probability judgment while probability judgment (β = 0.25, p = 0.029 ) was better than beliefs about risk in predicting subsequent influenza vaccination uptake. Beliefs about risk and feeling at risk seemed to predict the same aspect of subsequent vaccination uptake because their associations with vaccination uptake became insignificant when paired into the logistic regression model. Similarly, to compare the four scales for assessing probability judgment in predicting vaccination uptake, the 7-point verbal scale remained a significant and stronger predictor for vaccination uptake when paired with other three scales; the 6-point verbal scale was a significant and stronger predictor when paired with the percentage scale or the 2-point verbal scale; and the percentage scale was a significant and stronger predictor only when paired with the 2-point verbal scale.
Beliefs about risk and feeling at risk are not well differentiated by Hong Kong Chinese people. Feeling at risk, an affective-cognitive dimension of risk perception predicts subsequent vaccination uptake better than do probability judgments. Among the four scales for assessing risk probability judgment, the 7-point verbal scale offered the best predictive power for subsequent vaccination uptake.
Vaccination is the most effective way to prevent seasonal influenza and its severe outcomes. The objective of our study was to synthesize information on seasonal influenza vaccination policies, recommendations and practices in place in 2011 for all countries and areas in the Western Pacific Region of the World Health Organization (WHO).
Data were collected via a questionnaire on seasonal influenza vaccination policies, recommendations and practices in place in 2011.
Thirty-six of the 37 countries and areas (97%) responded to the survey. Eighteen (50%) reported having established seasonal influenza vaccination policies, an additional seven (19%) reported having recommendations for risk groups for seasonal influenza vaccination only and 11 (30%) reported having no policies or recommendations in place. Of the 25 countries and areas with policies or recommendations, health-care workers and the elderly were most frequently recommended for vaccination; 24 (96%) countries and areas recommended vaccinating these groups, followed by pregnant women (19 [76%]), people with chronic illness (18 [72%]) and children (15 [60%]). Twenty-six (72%) countries and areas reported having seasonal influenza vaccines available through public funding, private market purchase or both. Most of these countries and areas purchased only enough vaccine to cover 25% or less of their populations.
In light of the new WHO position paper on influenza vaccines published in 2012 and the increasing availability of country-specific data, countries and areas should consider reviewing or developing their seasonal influenza vaccination policies to reduce morbidity and mortality associated with annual epidemics and as part of ongoing efforts for pandemic preparedness.
Persons with high-risk conditions such as asthma were a target group for H1N1 vaccine recommendations. We conducted a mailed survey of a national sample of pulmonologists to understand their participation in the 2009-2010 H1N1 vaccine campaign. The response rate was 59%. The majority of pulmonologists strongly recommended H1N1 vaccine for children (73%) and adults aged 25–64 years (51%). Only 60% of respondents administered H1N1 vaccine in their practice compared to 87% who offered seasonal influenza vaccine. Other than vaccine supply, respondents who provided H1N1 vaccine reported few logistical problems. Two-thirds of respondents would be very likely to vaccinate during a future influenza pandemic; this rate was higher among those who provided H1N1 vaccine and/or seasonal flu vaccine. In total, the H1N1 vaccine-related experiences of pulmonologists seemed to be positive. However, additional efforts are needed to increase participation in future pandemic vaccination campaigns.
The Health Action Process Approach (HAPA) posits a distinction between pre-intentional motivation processes and a post-intentional volition process that leads to the actual behavior change. For smoking cessation, the HAPA predicts that increased risk perceptions would foster a decision to quit smoking. From a cross-sectional perspective, the HAPA predicts that those who do not intend to quit (non-intenders) should have lower risk perceptions than those who do intend to quit (intenders).
Adult smokers participated in a cross-sectional survey. Multiple measures of motivation to quit smoking and risk perceptions for smoking were assessed. ANOVA and contrast analysis were employed for data analysis.
The results were generally supportive of the HAPA. Non-intenders had systematically lower risk perceptions compared to intenders. Most of these findings were statistically significant.
The results demonstrated that risk perceptions distinguish non-intenders from intenders. These results suggest that smokers low in motivation to quit could benefit from information and reminders about the serious health problems caused by smoking.
Smoking; Motivation; Risk Perception; Health Action Process Approach
An experiment tested the pathways through which alcohol expectancies and intoxication influenced men’s self-reported sexual aggression intentions during an unprotected sexual encounter. After a questionnaire session, male social drinkers (N = 124) were randomly assigned to either an alcohol condition (target peak BAC = .08%) or a control condition. Upon completion of beverage consumption, participants read a description of a sexual encounter in which the female partner refused to have unprotected sexual intercourse. Participants then rated their emotional state, their intentions to have unprotected sex with the unwilling partner, and their post-incident perceptions of the encounter. Structural equation modeling indicated that intoxicated men reported feeling stronger sexual aggression congruent emotions/motivations such as arousal and anger; however, this effect was moderated by alcohol expectancies. Intoxicated participants with stronger alcohol-aggression expectancies reported greater sexual aggression congruent emotions/motivations than did intoxicated participants with weaker alcohol-aggression expectancies. For sober participants, alcohol-aggression expectancies did not influence emotions/motivations. In turn, stronger sexual assault congruent emotions/motivations predicted greater sexual aggression intentions. Men with greater sexual aggression intentions were less likely to label the situation as a sexual assault and reported less concern about their intended actions. These findings underscore the relevance of both alcohol expectancies and alcohol intoxication to sexual aggression perpetration and highlight the importance of including information about alcohol’s influence on both emotional and cognitive responses in sexual aggression prevention work.
Sexual Aggression; Alcohol; Unprotected Sex; Alcohol Expectancies
Individual perception of vaccine safety is an important factor in determining a person's adherence to a vaccination program and its consequences for disease control. This perception, or belief, about the safety of a given vaccine is not a static parameter but a variable subject to environmental influence. To complicate matters, perception of risk (or safety) does not correspond to actual risk. In this paper we propose a way to include the dynamics of such beliefs into a realistic epidemiological model, yielding a more complete depiction of the mechanisms underlying the unraveling of vaccination campaigns. The methodology proposed is based on Bayesian inference and can be extended to model more complex belief systems associated with decision models. We found the method is able to produce behaviors which approximate what has been observed in real vaccine and disease scare situations. The framework presented comprises a set of useful tools for an adequate quantitative representation of a common yet complex public-health issue. These tools include representation of beliefs as Bayesian probabilities, usage of logarithmic pooling to combine probability distributions representing opinions, and usage of natural conjugate priors to efficiently compute the Bayesian posterior. This approach allowed a comprehensive treatment of the uncertainty regarding vaccination behavior in a realistic epidemiological model.
A frequently made assumption in population models is that individuals make decisions in a standard way, which tends to be fixed and set according to the modeler's view on what is the most likely way individuals should behave. In this paper we acknowledge the importance of modeling behavioral changes (in the form of beliefs/opinions) as a dynamic variable in the model. We also propose a way of mathematically modeling dynamic belief updates which is based on the very well established concept of a belief as a probability distribution and its temporal evolution as a direct application of the Bayes theorem. We also propose the use of logarithmic pooling as an optimal way of combining different opinions which must be considered when making a decision. To argue for the relevance of this issue, we present a model of vaccinating behaviour with dynamic belief updates, modeled after real scenarios of vaccine and disease scare recorded in the recent literature.
Theoretical models of infection spread on networks predict that targeting vaccination at individuals with a very large number of contacts (superspreaders) can reduce infection incidence by a significant margin. These models generally assume that superspreaders will always agree to be vaccinated. Hence, they cannot capture unintended consequences such as policy resistance, where the behavioral response induced by a new vaccine policy tends to reduce the expected benefits of the policy. Here, we couple a model of influenza transmission on an empirically-based contact network with a psychologically structured model of influenza vaccinating behavior, where individual vaccinating decisions depend on social learning and past experiences of perceived infections, vaccine complications and vaccine failures. We find that policy resistance almost completely undermines the effectiveness of superspreader strategies: the most commonly explored approaches that target a randomly chosen neighbor of an individual, or that preferentially choose neighbors with many contacts, provide at best a relative improvement over their non-targeted counterpart as compared to when behavioral feedbacks are ignored. Increased vaccine coverage in super spreaders is offset by decreased coverage in non-superspreaders, and superspreaders also have a higher rate of perceived vaccine failures on account of being infected more often. Including incentives for vaccination provides modest improvements in outcomes. We conclude that the design of influenza vaccine strategies involving widespread incentive use and/or targeting of superspreaders should account for policy resistance, and mitigate it whenever possible.
Superspreaders are the small number of individuals responsible for the majority of infections. Theoretical models have shown how vaccinating superspreaders can be a highly efficient way to control disease. However, these models neglect behavior by assuming that superspreaders will always agree to be vaccinated. This is a problematic assumption for influenza vaccination, which is voluntary in most populations, and for which vaccine coverage is often suboptimal. We developed a model of seasonal influenza transmission on a network of individuals who make decisions about whether or not to get vaccinated based on known determinants of vaccine uptake, such as personal infection history, perceived vaccine risks, and social influences. We found that, because of feedbacks between disease spread and individual vaccinating behavior, attempts to boost vaccine coverage in superspreaders through the use of incentives or recruiting by social contacts are almost completely undermined by such feedbacks. For example, higher vaccine uptake in superspreaders reduces influenza incidence, which in the next season reduces the perceived need for vaccination among non-superspreaders, who then do not become vaccinated as much. Our results suggest that the design of potential strategies to reach influenza superspreaders should account for behavioral feedbacks, since they may blunt policy effectiveness.
The hierarchy of effects (HOE) model is often used in planning mass-reach communication campaigns to promote health, but has rarely been empirically tested. This paper examines Canada's 30 year ParticipACTION campaign to promote physical activity (PA). A cohort from the nationally representative 1981 Canada Fitness Survey was followed up in 1988 and 2002–2004. Modelling of these data tested whether the mechanisms of campaign effects followed the theoretical framework proposed in the HOE. Campaign awareness was measured in 1981. Outcome expectancy, attitudes, decision balance and future intention were asked in 1988. PA was assessed at all time points. Logistic regression was used to sequentially test mediating and moderating variables adjusting for age, sex and education. No selection bias was observed; however, relatively fewer respondents than non-respondents smoked or were underweight at baseline. Among those inactive at baseline, campaign awareness predicted outcome expectancy which in turn predicted positive attitude to PA. Positive attitudes predicted high decision balance, which predicted future intention. Future intention mediated the relationship between decision balance and sufficient activity. Among those sufficiently active at baseline, awareness was unrelated to outcome expectancy and inversely related to positive attitude. These results lend support to the HOE model, in that the effects of ParticipACTION's serial mass media campaigns were consistent with the sequential rollout of its messages, which in turn was associated with achieving an active lifestyle among those initially insufficiently active. This provides support to an often-used theoretical framework for designing health promotion media campaigns.
mass media; community intervention; population based; social marketing
Public adherence to influenza vaccination recommendations has been low, particularly among younger adults and children under 2, despite the availability of safe and effective seasonal vaccine. Intention to receive 2009 pandemic influenza A (H1N1) vaccine has been estimated to be 50% in select populations. This report measures knowledge of and intention to receive pandemic vaccine in a population-based setting, including target groups for seasonal and H1N1 influenza.
Methodology and Principal Findings
On August 28–29, 2009, we conducted a population-based survey in 2 counties in North Carolina. The survey used the 30×7 two-stage cluster sampling methodology to identify 210 target households. Prevalence ratios (PR) and 95% confidence intervals (CI) were estimated. Knowledge of pandemic influenza A (H1N1) vaccine was high, with 165 (80%) aware that a vaccine was being prepared. A total of 133 (64%) respondents intended to receive pandemic vaccine, 134 (64%) intended to receive seasonal vaccine, and 109 (53%) intended to receive both. Reporting great concern about H1N1 infection (PR 1.55; 95%CI: 1.30, 1.85), receiving seasonal influenza vaccine in 2008–09 (PR 1.47; 95%CI: 1.18, 1.82), and intending to receive seasonal influenza vaccine in 2009–10 (PR 1.27; 95%CI: 1.14, 1.42) were associated with intention to receive pandemic vaccine. Not associated were knowledge of vaccine, employment, having children under age 18, gender, race/ethnicity and age. Reasons cited for not intending to get vaccinated include not being at risk for infection, concerns about vaccine side effects and belief that illness caused by pandemic H1N1 would be mild. Forty-five percent of households with children under 18 and 65% of working adults reported ability to comply with self-isolation at home for 7–10 days if recommended by authorities.
Conclusions and Significance
This is the first report of a population based rapid assessment used to assess knowledge and intent to receive pandemic vaccine in a community sample. Intention to receive pandemic and seasonal vaccines was higher than previously published reports. To reach persons not intending to receive pandemic vaccine, public health communications should focus on the perceived risk of infection and concerns about vaccine safety.
There has been worldwide interest in the safety of the pandemic influenza A (H1N1p) vaccines, although limited data are available from the vaccine recipients’ perspective. This evaluation was designed to collect data from people who had received an influenza vaccination during the 2009–2010 season using a web-based data collection tool supplemented by telephone reporting (PROBE).
People scheduled to receive the influenza A (H1N1p) or seasonal influenza vaccines were recruited through media advertising and campaigns throughout the West of Scotland. Vaccine recipients participated in the evaluation by answering demographic and side effect questions using PROBE methodology on the day of the immunization, after 3 days, 8 days, 6 weeks, 12 weeks, and 26 weeks.
A total of 1103 vaccine recipients including 134 young children (0–4 years) participated in the evaluation; 694 (63%) received H1N1p vaccine only, 135 (12%) seasonal vaccine only, 224 (20%) both H1N1p and seasonal vaccines, and 50 (5%) received H1N1p or seasonal vaccine with a non-influenza vaccine (eg, travel or pneumococcal). Overall, 42% of recipients reported experiencing a side effect after their baseline vaccination; the most commonly reported were general and arm side effects (>20%). Injection site discomfort/pain and flu-like symptoms were reported by 57% and 24% of recipients, respectively. A significantly higher proportion of the 960 H1N1p vaccine recipients experienced a side effect (44% vs 27%, P < 0.001) or injection site discomfort/pain (61% vs 26%, P < 0.001) than those receiving seasonal influenza vaccines. Female sex and H1N1p vaccination were associated with a significantly higher risk of injection site discomfort/pain, whereas the 70+ age group was associated with a significantly lower risk. H1N1p vaccine was well tolerated by children under 5 years with side effects reported at a similar frequency to that found in the total population.
Safety and tolerability data from influenza vaccine recipients including young children (via parents/carers) can be effectively collected using an online questionnaire with a telephone option (PROBE). The influenza A (H1N1p) vaccine was well tolerated, but was associated with more local short-term reactions than the seasonal influenza vaccine.
safety; influenza; vaccination; H1N1; patient reported outcomes; side effects
Population aging raises concerns regarding the increases in the rates of morbidity and mortality that result from influenza and its complications. Although vaccination is the most important tool for preventing influenza, vaccination program among high-risk groups has not reached its predetermined aims in several settings. This study aimed to evaluate the impacts of clinical and demographic factors on vaccine compliance among the elderly in a setting that includes a well-established annual national influenza vaccination campaign.
This cross-sectional study included 134 elderly patients who were regularly followed in an academic medical institution and who were evaluated for their influenza vaccination uptake within the last five years; in addition, the demographic and clinical characteristics and the reasons for compliance or noncompliance with the vaccination program were investigated.
In total, 67.1% of the participants received the seasonal influenza vaccine in 2009. Within this vaccination-compliant group, the most common reason for vaccine uptake was the annual nationwide campaign (52.2%; 95% CI: 41.4–62.9%); compared to the noncompliant group, a higher percentage of compliant patients had been advised by their physician to take the vaccine (58.9% vs. 34.1%; p<0.01).
The education of patients and health care professionals along with the implementation of immunization campaigns should be evaluated and considered by health authorities as essential for increasing the success rate of influenza vaccination compliance among the elderly.
Influenza immunization; Campaign; Medical recommendation; Adherence; Geriatric
Objective: To examine illness/vaccination perceptions of and intentions to vaccinate for seasonal influenza (SI) and 2009 H1N1 in the college setting.
Participants: 1190 adults [M=23.5 years (SD=9.5)] from a university in the North-Eastern U.S.
Methods: We deployed a web-based survey via campus email just prior to the 2009 H1N1 vaccine release.
Results: Younger adults (18-24 years) had lesser understanding of the difference between influenza types, and they reported less regular and current SI vaccination compared to older adults (25-64 years). Younger respondents perceived lesser likelihood of illness from, but attributed greater severity to H1N1 versus SI. Regularity of SI vaccination and perceived vaccine efficacy were the strongest predictors of intent to vaccinate against H1N1, followed by perceived likelihood of illness and confidence in what experts know about vaccine safety.
Conclusions: Young adults in college may require additional information during novel influenza pandemics. Measuring perceptions and past vaccination behaviors may facilitate targeting of preventive efforts in the college setting.
Two antigenically distinct lineages of influenza B viruses have circulated globally since 1985. However, licensed trivalent seasonal influenza vaccines contain antigens from only a single influenza B virus and thus provide limited immunity against circulating influenza B strains of the lineage not present in the vaccine. In recent years, predictions about which B lineage will predominate in an upcoming influenza season have been no better than chance alone, correct in only 5 of the 10 seasons from 2001 to 2011. Consequently, seasonal influenza vaccines could be improved by inclusion of influenza B strains of both lineages. The resulting quadrivalent influenza vaccines would allow influenza vaccination campaigns to respond more effectively to current global influenza epidemiology. Manufacturing capacity for seasonal influenza vaccines has increased sufficiently to supply quadrivalent influenza vaccines, and methods to identify the influenza B strains to include in such vaccines are in place. Multiple manufacturers have initiated clinical studies of quadrivalent influenza vaccines. Data from those studies, taken together with epidemiologic data regarding the burden of disease caused by influenza B infections, will determine the safety, effectiveness, and benefit of utilizing quadrivalent vaccines for the prevention of seasonal influenza disease.
influenza; public health; quadrivalent; surveillance; vaccine