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1.  Removing the Age Restrictions for Rotavirus Vaccination: A Benefit-Risk Modeling Analysis 
PLoS Medicine  2012;9(10):e1001330.
A modeling analysis conducted by Manish Patel and colleagues predicts the possible number of rotavirus deaths prevented, and number of intussusception deaths caused, by use of an unrestricted rotavirus schedule in low- and middle-income countries.
Background
To minimize potential risk of intussusception, the World Health Organization (WHO) recommended in 2009 that rotavirus immunization should be initiated by age 15 weeks and completed before 32 weeks. These restrictions could adversely impact vaccination coverage and thereby its health impact, particularly in developing countries where delays in vaccination often occur.
Methods and Findings
We conducted a modeling study to estimate the number of rotavirus deaths prevented and the number of intussusception deaths caused by vaccination when administered on the restricted schedule versus an unrestricted schedule whereby rotavirus vaccine would be administered with DTP vaccine up to age 3 years. Countries were grouped on the basis of child mortality rates, using WHO data. Inputs were estimates of WHO rotavirus mortality by week of age from a recent study, intussusception mortality based on a literature review, predicted vaccination rates by week of age from USAID Demographic and Health Surveys, the United Nations Children's Fund (UNICEF) Multiple Indicator Cluster Surveys (MICS), and WHO-UNICEF 2010 country-specific coverage estimates, and published estimates of vaccine efficacy and vaccine-associated intussusception risk. On the basis of the error estimates and distributions for model inputs, we conducted 2,000 simulations to obtain median estimates of deaths averted and caused as well as the uncertainty ranges, defined as the 5th–95th percentile, to provide an indication of the uncertainty in the estimates.
We estimated that in low and low-middle income countries a restricted schedule would prevent 155,800 rotavirus deaths (5th–95th centiles, 83,300–217,700) while causing potentially 253 intussusception deaths (76–689). In contrast, vaccination without age restrictions would prevent 203,000 rotavirus deaths (102,000–281,500) while potentially causing 547 intussusception deaths (237–1,160). Thus, removing the age restrictions would avert an additional 47,200 rotavirus deaths (18,700–63,700) and cause an additional 294 (161–471) intussusception deaths, for an incremental benefit-risk ratio of 154 deaths averted for every death caused by vaccine. These extra deaths prevented under an unrestricted schedule reflect vaccination of an additional 21%–25% children, beyond the 63%–73% of the children who would be vaccinated under the restricted schedule. Importantly, these estimates err on the side of safety in that they assume high vaccine-associated risk of intussusception and do not account for potential herd immunity or non-fatal outcomes.
Conclusions
Our analysis suggests that in low- and middle-income countries the additional lives saved by removing age restrictions for rotavirus vaccination would far outnumber the potential excess vaccine-associated intussusception deaths.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Rotavirus causes severe diarrhea and vomiting. It is responsible for a large number of hospitalizations among young children in developed countries (an estimated 60,000 hospitalizations per year in the US in 2005, for example). In poor countries, rotavirus is a major cause of death in children under five. In 1998, the first rotavirus vaccine, called RotaShield, was approved in the US by the Food and Drug Administration. Shortly after the vaccine became widely used, doctors noticed a small increase in a problem called intussusception among the vaccinated infants. Intussusception is a rare type of bowel obstruction that occurs when the bowel telescopes in on itself. Prompt treatment of intussusception normally leads to full recovery, but some children with the condition need surgery, and when the disease is left untreated it can be fatal. Because intussusception is a serious condition and because very few children die from rotavirus infection in the United States, the US authorities stopped recommending vaccination with RotaShield in 1999. The manufacturer withdrew the vaccine from the market shortly thereafter.
Since then, two new vaccines (named Rotarix and RotaTeq) have been developed. Before they were approved in the US and elsewhere, they were extensively tested for any adverse side effects, especially intussusception. No increase in the risk for intussusception was found in these studies, and both are now approved and recommended for vaccination of infants around the world.
Why Was This Study Done?
Since 2006, hundreds of thousands of infants have been vaccinated with Rotarix or RotaTeq, with safety being closely monitored. Some countries have reported a small increase in intussusception (one to four additional cases per 100,000 vaccinated infants, compared with one per 2,000 of cases that occur in unvaccinated children). This increase is much lower than the one seen previously with RotaShield. In response to these findings, authorities in the US and other developed countries as well as the World Health Organization declared that the benefits of the vaccine outweigh the risks of the small number of additional intussusception cases in both developed and poor countries. However, because older infants have a higher risk of naturally occurring intussusception, they decided that the course of vaccination (three oral doses for Rotarix and two for RotaTeq) should be initiated before 15 weeks of age and completed before the age of 32 weeks. This is usually not a problem in countries with easy access to health facilities. However, in many poor countries where delays in infant vaccination are common, giving the vaccine only to very young children means that many others who could benefit from its protection will be excluded. In this study, the researchers examined the risks and benefits of rotavirus vaccination in poor countries where most of the rotavirus deaths occur. Specifically, they looked at the benefits and risks if the age restrictions were removed, with a particular emphasis on allowing infants to initiate rotavirus immunization even if they arrive after 15 weeks of age.
What Did the Researchers Do and Find?
The researchers used the most recent estimates for how well the vaccines protect children in Africa and Asia from becoming infected with rotavirus, how many deaths from rotavirus infection can be avoided by vaccination, how many additional cases of intussusception will likely occur in vaccinated children, and what proportion of children would be excluded from rotavirus vaccination because they are too old when they come to a health facility for their infant vaccination. They then estimated the number of rotavirus deaths prevented and the number of intussusception deaths caused by vaccination in two scenarios. The first one (the restricted scenario) corresponds to previous guidelines from WHO and others, in which rotavirus vaccination needs to be initiated before 15 weeks and the full series completed before 32 weeks. The second one (called the unrestricted scenario) allows rotavirus vaccination of children alongside current routinely administered vaccines up to three years of age, recognizing that most children receive their vaccination by 1 year of life.
The researchers estimated that removing the age restriction would prevent an additional 154 rotavirus deaths for each intussusception death caused by the vaccine. Under the unrestricted scenario, roughly a third more children would get vaccinated, which would prevent an additional approximately 47,000 death from rotavirus while causing approximately 300 additional intussusception deaths.
They also calculated some best- and worst-case scenarios. The worst-case scenario assumed a much higher risk of intussusception for children receiving their first dose after 15 weeks of life than what has been seen anywhere, and also that an additional 20% of children with intussusception would die from it than what was already assumed in their routine scenario (again, a higher number than seen in reality). In addition, it assumes a lower protection from rotavirus death for the vaccine than has been observed in children vaccinated so far. In this pessimistic case, the number of rotavirus deaths prevented was 24 for each intussusception death caused by the vaccine.
What Do These Findings Mean?
If one accepts that deaths caused by a vaccine are not fundamentally different from deaths caused by a failure to vaccinate, then these results show that the benefits of lifting the age restriction for rotavirus vaccine clearly outweigh the risks, at least when only examining mortality outcomes. The calculations are valid only for low-income countries in Africa and Asia where both vaccination delays and deaths from rotavirus are common. The risk-benefit ratio will be different elsewhere. There are also additional risks and benefits that are not included in the study's estimates. For example, early vaccination might be seen as less of an urgent priority when this vaccine can be had at a later date, leaving very young children more vulnerable. On the other hand, when many children in the community are vaccinated, even the unvaccinated children are less likely to get infected (what is known as “herd immunity”), something that has not been taken into account in the benefits here. The results of this study (and its limitations) were reviewed in April 2012 by WHO's Strategic Advisory Group of Experts. The group then recommended that, while early vaccination is still strongly encouraged, the age restriction on rotavirus vaccination should be removed in countries where delays in vaccination and rotavirus mortality are common so that more vulnerable children can be vaccinated and deaths from rotavirus averted.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001330.
The World Health Organization provides information on rotavirus
Wikipedia has information on rotavirus vaccine and intussusception (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The US Centers for Disease Control and Prevention rotavirus vaccination page includes a link to frequently asked questions
PATH Rotavirus Vaccine Access and Delivery has timely, useful updates on status of rotavirus vaccines globally
doi:10.1371/journal.pmed.1001330
PMCID: PMC3479108  PMID: 23109915
2.  Rotarix in Japan: Expectations and Concerns 
Biologics in Therapy  2011;1(1):4.
A live-attenuated, orally-administered, monovalent, human rotavirus vaccine, Rotarix® (GlaxoSmithKline Biologicals, Rixensart, Belgium), was licensed and launched in 2011 as the first rotavirus vaccine in Japan. The rotavirus causes a substantial disease burden with an estimated 790,000 outpatient visits, 27,000–78,000 hospitalizations, and approximately 10 deaths each year in Japan. Since a recent clinical trial showed that Rotarix was as efficacious in Japan as in other industrialized countries, it is expected that the annual number of rotavirus hospitalizations will be reduced to between 1000–3000, and that outpatient visits will be reduced to 200,000. The universal rotavirus immunization program with Rotarix was calculated to be at the threshold of being cost-effective, even from the healthcare perspective, and it was highly cost-effective from the societal perspective, assuming that Rotarix is co-administered with other childhood vaccines. While Rotarix contains only a single G1P[8] human rotavirus, the postlicensure studies in Brazil showed that Rotarix provided a 75%–85% protective efficacy against severe dehydrating diarrhea or hospitalizations due to fully-heterotypic G2P[4] strains. While postlicensure studies detected a small and finite risk of intussusception associated with the administration of Rotarix, the authors conclude that Rotarix is safe to administer to infants between 6-12 weeks of age for the first dose and by 24 weeks of age for the second dose. However, the authors strongly discourage the delayed administration of the first dose between 13-20 weeks of age, which is allowed without any warning. Given the high incidence of naturally-occurring intussusception in Japan (185 cases per 100,000 children/year among children less than 1 year of age), this should prevent pediatricians and parents from having ill-perceptions of Rotarix being associated with an increased number of temporally-associated intussusception, and fully appreciate the benefit of the rotavirus vaccine.
doi:10.1007/s13554-011-0007-5
PMCID: PMC3873079  PMID: 24392294
diarrhea; heterotypic immunity; immunization; intussusception; Japan; Rotarix; rotavirus
3.  Rotarix in Japan: Expectations and Concerns 
Biologics in Therapy  2011;1(1):4.
A live-attenuated, orally-administered, monovalent, human rotavirus vaccine, Rotarix® (GlaxoSmithKline Biologicals, Rixensart, Belgium), was licensed and launched in 2011 as the first rotavirus vaccine in Japan. The rotavirus causes a substantial disease burden with an estimated 790,000 outpatient visits, 27,000–78,000 hospitalizations, and approximately 10 deaths each year in Japan. Since a recent clinical trial showed that Rotarix was as efficacious in Japan as in other industrialized countries, it is expected that the annual number of rotavirus hospitalizations will be reduced to between 1000–3000, and that outpatient visits will be reduced to 200,000. The universal rotavirus immunization program with Rotarix was calculated to be at the threshold of being cost-effective, even from the healthcare perspective, and it was highly cost-effective from the societal perspective, assuming that Rotarix is co-administered with other childhood vaccines. While Rotarix contains only a single G1P[8] human rotavirus, the postlicensure studies in Brazil showed that Rotarix provided a 75%–85% protective efficacy against severe dehydrating diarrhea or hospitalizations due to fully-heterotypic G2P[4] strains. While postlicensure studies detected a small and finite risk of intussusception associated with the administration of Rotarix, the authors conclude that Rotarix is safe to administer to infants between 6-12 weeks of age for the first dose and by 24 weeks of age for the second dose. However, the authors strongly discourage the delayed administration of the first dose between 13-20 weeks of age, which is allowed without any warning. Given the high incidence of naturally-occurring intussusception in Japan (185 cases per 100,000 children/year among children less than 1 year of age), this should prevent pediatricians and parents from having ill-perceptions of Rotarix being associated with an increased number of temporally-associated intussusception, and fully appreciate the benefit of the rotavirus vaccine.
doi:10.1007/s13554-011-0007-5
PMCID: PMC3873079  PMID: 24392294
diarrhea; heterotypic immunity; immunization; intussusception; Japan; Rotarix; rotavirus
4.  Efficacy of human rotavirus vaccine against severe gastroenteritis in Malawian children in the first two years of life: a randomised, double-blind, placebo controlled trial 
Vaccine  2012;30(0 1):A36-A43.
Rotavirus gastroenteritis is a major cause of morbidity and mortality among African infants and young children. A phase III, placebo-controlled, multi-centre clinical trial of a live, oral G1P[8] human rotavirus vaccine (RIX4414) undertaken in Malawi and South Africa significantly reduced the incidence of severe rotavirus gastroenteritis in the first year of life. We now report on vaccine efficacy in the Malawi cohort of children who were followed into the second year of life. A total of 1,773 healthy infants were enrolled in Blantyre, Malawi into three groups. Two groups received three doses of RIX4414 or placebo at age 6, 10, and 14 weeks and the third group received placebo at 6 weeks and RIX4414 at age 10 and 14 weeks. Subjects were followed by weekly home visits for episodes of gastroenteritis until 1 year of age, and were then re-consented for further follow-up to 18-24 months of age. Severity of gastroenteritis episodes was graded according to the Vesikari scoring system. Seroconversion for anti-rotavirus IgA was determined on a subset of children by using ELISA on pre- and post-vaccine blood samples. Rotavirus VP7 (G) and VP4 (P) genotypes were determined by RT-PCR. A total of 70/1030 (6.8%, 95% CI 5.3 - 8.5) subjects in the pooled (2 dose plus 3 dose) RIX4414 group compared with 53/483 (11.0%, 8.3 – 14.1) subjects in the placebo group developed severe rotavirus gastroenteritis in the entire follow-up period (Vaccine Efficacy 38.1% (9.8 – 57.3). The point estimate of efficacy in the second year of life (17.6%; −59.2 – 56.0) was lower than in the first year of life (49.4%; 19.2 – 68.3). There were non-significant trends towards a higher efficacy in the second year of life among children who received the three-dose schedule compared with the two-dose schedule, and a higher anti-rotavirus IgA seroresponse rate in the three-dose RIX4414 group. Rotavirus strains detected included genotype G12 (31%); G9 (23%); and G8 (18%); only 18% of strains belonged to the G1P[8] genotype. While the optimal dosing schedule of RIX4414 in African infants requires further investigation, vaccination with RIX4414 significantly reduced the incidence of severe gastroenteritis caused by diverse rotavirus strains in an impoverished African population with high rotavirus disease burden in the first two years of life.
doi:10.1016/j.vaccine.2011.09.120
PMCID: PMC3982044  PMID: 22520135
Gastroenteritis; Rotavirus; Vaccine; Genotypes
5.  Molecular characterization of rotavirus strains detected during a clinical trial of a human rotavirus vaccine in Blantyre, Malawi 
Vaccine  2012;30(0 1):A140-A151.
The human, G1P[8] rotavirus vaccine (Rotarix) significantly reduced severe rotavirus gastroenteritis episodes in a clinical trial in South Africa and Malawi, but vaccine efficacy was lower in Malawi (49.5%) than reported in South Africa (76.9%) and elsewhere. The aim of this study was to examine the molecular relationships of circulating wild-type rotaviruses detected during the clinical trial in Malawi to RIX4414 (the strain contained in Rotarix) and to common human rotavirus strains. Of 88 rotavirus-positive, diarrhoeal stool specimens, 43 rotaviruses exhibited identifiable RNA migration patterns when examined by polyacrylamide gel electrophoresis. The genes encoding VP7, VP4, VP6 and NSP4 of 5 representative strains possessing genotypes G12P[6], G1P[8], G9P[8], and G8P[4] were sequenced. While their VP7 (G) and VP4 (P) genotype designations were confirmed, the VP6 (I) and NSP4 (E) genotypes were either I1E1 or I2E2, indicating that they were of human rotavirus origin. RNA-RNA hybridization using 21 culture-adapted strains showed that Malawian rotaviruses had a genomic RNA constellation common to either the Wa-like or DS-1 like human rotaviruses. Overall, the Malawi strains appear similar in their genetic make-up to rotaviruses described in countries where vaccine efficacy is greater, suggesting that the lower efficacy in Malawi is unlikely to be explained by the diversity of circulating strains.
doi:10.1016/j.vaccine.2011.09.119
PMCID: PMC3982048  PMID: 22520123
Rotavirus; vaccine; genotype; strain diversity; genogroup
6.  Rotavirus Antigenemia in Children Is Associated with Viremia 
PLoS Medicine  2007;4(4):e121.
Background
Antigenemia is commonly detected in rotavirus-infected children. Although rotavirus RNA has been detected in serum, definitive proof of rotavirus viremia has not been shown. We aimed to analyze a defined patient population to determine if infectious virus could be detected in sera from children with rotavirus antigenemia.
Methods and Findings
Serum samples obtained upon hospitalization from children with gastroenteritis (57 stool rotavirus-positive and 41 rotavirus-negative), children with diagnosed bronchiolitis of known (n = 58) or unknown (n = 17) viral etiology, children with noninfectious, nonchronic conditions (n = 17), and healthy adults (n = 28) were tested for rotavirus antigen by enzyme immunoassay (EIA). Results of serum antigen testing were assessed for association with clinical and immunological attributes of the children. Rotavirus antigenemia was detected in 90% (51/57) of children with rotavirus-positive stools, in 89% (8/9) of children without diarrhea but with rotavirus-positive stools, in 12% (2/17) of children with bronchiolitis of unknown etiology without gastroenteritis, and in 12% (5/41) of children with gastroenteritis but with rotavirus-negative stools. Antigenemia was not detected in sera from children with noninfectious nonchronic conditions, children with bronchiolitis of known etiology and no gastroenteritis, or healthy adults. Neither age nor timing of serum collection within eight days after onset of gastroenteritis significantly affected levels of antigenemia, and there was no correlation between antigenemia and viral genotype. However, there was a negative correlation between serum rotavirus antigen and acute rotavirus-specific serum IgA (r = −0.44, p = 0.025) and IgG (r = −0.40, p = 0.01) titers. We examined 11 antigen-positive and nine antigen-negative sera for infectious virus after three blind serial passages in HT-29 cells using immunofluorescence staining for rotavirus structural and nonstructural proteins. Infectious virus was detected in 11/11 (100%) sera from serum antigen-positive children and in two out of nine (22%) sera samples from antigen-negative children (p = 0.002).
Conclusions
Most children infected with rotavirus are viremic. The presence of viremia is directly related to the detection of antigenemia and is independent of the presence of diarrhea. Antigenemia load is inversely related to the titer of antirotavirus antibody in the serum. The finding of infectious rotavirus in the blood suggests extraintestinal involvement in rotavirus pathogenesis; however, the impact of rotavirus viremia on clinical manifestations of infection is unknown.
A study of 57 children with rotavirus-positive stools found that most were viremic, and that the presence of viremia was directly related to antigenemia and independent of the presence of diarrhea.
Editors' Summary
Background.
Rotavirus is a type of virus that is the commonest cause of severe diarrhea among children worldwide. It is passed from one person to another when virus present in the stool of an infected person is swallowed by another individual. The infection causes vomiting, watery diarrhea, and fever; many children need to be hospitalized as a result and globally more than 600,000 children are thought to die as a result of rotavirus infections per year. Evidence from single case descriptions of infected children have suggested that rotavirus might also cause symptoms outside of the gut—for example, in the lungs or brain. Previous studies have found fragments of rotavirus, for example RNA or parts of virus protein, in tissues outside of the gut such as liver, kidney, blood, and heart. However, simply finding fragments such as RNA or protein does not necessarily mean that rotavirus infects these tissues.
Why Was This Study Done?
These researchers wanted to find out whether rotavirus was present in the blood of infected children. If evidence of rotavirus in the blood was found, this might help explain why some children infected with rotavirus have symptoms affecting organs other than the gut.
What Did the Researchers Do and Find?
In this study, five groups of patients were recruited and tests were done on each to find out whether infectious rotavirus was present in their bloodstream, and also whether the researchers could detect rotavirus components in blood using antibodies against particular parts of the rotavirus particle. The five groups of patients that were compared included children hospitalized with gastroenteritis; children hospitalized with noninfectious conditions; healthy adult laboratory workers; children with lung infections from known viruses; and finally children with lung infections of unknown cause. The researchers found that among the children with gastroenteritis who had rotavirus in their stool, 90% also had evidence of rotavirus particles in their bloodstream. By contrast, control individuals (either children who were hospitalized with noninfectious conditions or healthy adults) did not have rotavirus particles in blood. A small proportion of children with gastroenteritis but no rotavirus in their stool did have rotavirus particles in blood. Interestingly, a small proportion of the children who had lung infections (but in whom no known virus had been identified as the cause) showed evidence of rotavirus in their bloodstreams. Finally, in a group of 11 children with evidence of rotavirus particles in their bloodstreams, all were found to also have infectious virus present in the blood.
What Do These Findings Mean?
These results show that rotavirus is able to spread beyond the gut and into the bloodstream. The finding that rotavirus can spread into the bloodstream may explain some earlier suggestions that rotavirus is responsible for symptoms outside of the gut. However, it is not yet clear how commonly children with rotavirus have other symptoms resulting from the virus spreading into their bloodstream.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040121.
Read the related PLoS Medicine Perspective article by David Candy
Information from the World Health Organization Initiative for Vaccine Research on rotavirus disease burden; see also the Rotavirus Vaccine Program, a partnership that aims to develop rotavirus vaccines appropriate for use in developing countries
Information from the US Centers for Disease Control and Prevention about rotavirus
Health Encyclopedia entry from the UK's NHS Direct on Rotavirus
doi:10.1371/journal.pmed.0040121
PMCID: PMC1852122  PMID: 17439294
7.  Pharmacoeconomic Spotlight on Rotavirus Vaccine RIX4414 (Rotarix™) in Developed Countries 
Drugs in R&d  2012;12(4):239-244.
The most common cause of severe diarrhea in infants and young children is rotavirus gastroenteritis (RVGE), which is associated with significant morbidity, healthcare resource use, and direct and indirect costs in industrialized nations. The monovalent rotavirus vaccine RIX4414 (Rotarix™) is administered as a two-dose oral series in infants and has demonstrated protective efficacy against RVGE in clinical trials conducted in developed countries. In addition, various naturalistic studies have demonstrated ‘real-world’ effectiveness after the introduction of widespread rotavirus vaccination programs in the community setting.
Numerous cost-effectiveness analyses have been conducted in developed countries in which a universal rotavirus vaccination program using RIX4414 was compared with no universal rotavirus vaccination program. There was a high degree of variability in base-case results across studies even when the studies were conducted in the same country, often reflecting differences in the selection of data sources or assumptions used to populate the models. In addition, results were sensitive to plausible changes in a number of key input parameters. As such, it is not possible to definitively state whether a universal rotavirus vaccination program with RIX4414 is cost effective in developed countries, although results of some analyses in some countries suggest this is the case. In addition, international guidelines advocate universal vaccination of infants and children against rotavirus. It is also difficult to draw conclusions regarding the cost effectiveness of rotavirus vaccine RIX4414 relative to that of the pentavalent rotavirus vaccine, which is administered as a three-dose oral series. Although indirect comparisons in cost-effectiveness analyses indicate that RIX4414 provided more favorable incremental cost-effectiveness ratios when each vaccine was compared with no universal rotavirus vaccination program, results were generally sensitive to vaccine costs. Actual tender prices of a full vaccination course for each vaccine were not known at the time of the analyses and therefore had to be estimated.
doi:10.2165/11208130-000000000-00000
PMCID: PMC3586123  PMID: 23017130
8.  Pharmacoeconomic Spotlight on Rotavirus Vaccine RIX4414 (Rotarix™) in Developed Countries 
Drugs in R&D  2012;12(4):239-244.
The most common cause of severe diarrhea in infants and young children is rotavirus gastroenteritis (RVGE), which is associated with significant morbidity, healthcare resource use, and direct and indirect costs in industrialized nations. The monovalent rotavirus vaccine RIX4414 (Rotarix™) is administered as a two-dose oral series in infants and has demonstrated protective efficacy against RVGE in clinical trials conducted in developed countries. In addition, various naturalistic studies have demonstrated ‘real-world’ effectiveness after the introduction of widespread rotavirus vaccination programs in the community setting.
Numerous cost-effectiveness analyses have been conducted in developed countries in which a universal rotavirus vaccination program using RIX4414 was compared with no universal rotavirus vaccination program. There was a high degree of variability in base-case results across studies even when the studies were conducted in the same country, often reflecting differences in the selection of data sources or assumptions used to populate the models. In addition, results were sensitive to plausible changes in a number of key input parameters. As such, it is not possible to definitively state whether a universal rotavirus vaccination program with RIX4414 is cost effective in developed countries, although results of some analyses in some countries suggest this is the case. In addition, international guidelines advocate universal vaccination of infants and children against rotavirus. It is also difficult to draw conclusions regarding the cost effectiveness of rotavirus vaccine RIX4414 relative to that of the pentavalent rotavirus vaccine, which is administered as a three-dose oral series. Although indirect comparisons in cost-effectiveness analyses indicate that RIX4414 provided more favorable incremental cost-effectiveness ratios when each vaccine was compared with no universal rotavirus vaccination program, results were generally sensitive to vaccine costs. Actual tender prices of a full vaccination course for each vaccine were not known at the time of the analyses and therefore had to be estimated.
doi:10.2165/11208130-000000000-00000
PMCID: PMC3586123  PMID: 23017130
9.  Decline in Diarrhea Mortality and Admissions after Routine Childhood Rotavirus Immunization in Brazil: A Time-Series Analysis 
PLoS Medicine  2011;8(4):e1001024.
A time series analysis by Manish Patel and colleagues shows that the introduction of rotavirus vaccination in Brazil is associated with reduced diarrhea-related deaths and hospital admissions in children under 5 years of age.
Background
In 2006, Brazil began routine immunization of infants <15 wk of age with a single-strain rotavirus vaccine. We evaluated whether the rotavirus vaccination program was associated with declines in childhood diarrhea deaths and hospital admissions by monitoring disease trends before and after vaccine introduction in all five regions of Brazil with varying disease burden and distinct socioeconomic and health indicators.
Methods and Findings
National data were analyzed with an interrupted time-series analysis that used diarrhea-related mortality or hospitalization rates as the main outcomes. Monthly mortality and admission rates estimated for the years after rotavirus vaccination (2007–2009) were compared with expected rates calculated from pre-vaccine years (2002–2005), adjusting for secular and seasonal trends. During the three years following rotavirus vaccination in Brazil, rates for diarrhea-related mortality and admissions among children <5 y of age were 22% (95% confidence interval 6%–44%) and 17% (95% confidence interval 5%–27%) lower than expected, respectively. A cumulative total of ∼1,500 fewer diarrhea deaths and 130,000 fewer admissions were observed among children <5 y during the three years after rotavirus vaccination. The largest reductions in deaths (22%–28%) and admissions (21%–25%) were among children younger than 2 y, who had the highest rates of vaccination. In contrast, lower reductions in deaths (4%) and admissions (7%) were noted among children two years of age and older, who were not age-eligible for vaccination during the study period.
Conclusions
After the introduction of rotavirus vaccination for infants, significant declines for three full years were observed in under-5-y diarrhea-related mortality and hospital admissions for diarrhea in Brazil. The largest reductions in diarrhea-related mortality and hospital admissions for diarrhea were among children younger than 2 y, who were eligible for vaccination as infants, which suggests that the reduced diarrhea burden in this age group was associated with introduction of the rotavirus vaccine. These real-world data are consistent with evidence obtained from clinical trials and strengthen the evidence base for the introduction of rotavirus vaccination as an effective measure for controlling severe and fatal childhood diarrhea.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Diarrheal disease, usually caused by infectious agents, is the second major cause of death in children aged under five years. As highlighted in a recent PLoS Medicine series, access to clean water and improved sanitation is the key to the primary prevention of diarrheal illnesses. Yet despite the targets of Millennium Development Goal 7 to half the number of people without access to clean water or improved sanitation by 2015, over one billion people worldwide do not currently have access to clean water and over two billion do not currently have access to improved sanitation.
Since enteric viruses are primarily transmitted directly from one person to another, they cannot be controlled completely by improvements in sanitation. Therefore, although not replacing the urgent need to provide access to clean water and improved sanitation for all, vaccination programs that protect young children against some infections that cause diarrhea, such as rotavirus, which accounts for one-third of all child deaths caused by diarrhea, are a pragmatic way forward. As large clinical trials have shown the safety and efficacy of rotavirus vaccines in population settings, in July 2009, the World Health Organization recommended including rotavirus vaccines into every country's national immunization programs.
Why Was This Study Done?
Although the protective effect of rotavirus vaccines has been assessed in various high-, middle-, and low-income settings, for reasons that remain unclear, the efficacy of live, oral rotavirus vaccines appears to be dependent on geographical location and correlated to the socioeconomic status of the population. Because of these concerns, evaluating the health impact of large-scale rotavirus vaccine programs and ensuring their equity in a real-world setting (rather than in clinical trial conditions) is important.
Therefore, the researchers addressed this issue by conducting this study to evaluate the effect of rotavirus vaccination on mortality and hospital admissions for diarrhea due to all causes among young children in the five regions of Brazil. The researchers chose to do this study in Brazil because of the high incidence of diarrhea-related deaths and hospital admissions and because five years ago, in July 2006, the Brazilian Ministry of Health introduced the single-strain rotavirus vaccine simultaneously in all 27 states through its national immunization program—allowing for “before” and “after” intervention analysis.
What Did the Researchers Do and Find?
The researchers obtained data on diarrheal deaths and hospital admissions in children aged under five years for the period 2002–2005 and 2007–2009 and data on rotavirus vaccination rates. The researchers got the data on diarrhea deaths from the Brazilian Mortality Information System—the national database of information collected from death certificates that covers 90% of all deaths in Brazil. The data on hospital admissions came from the electronic Hospital Information System of Brazil's Unified Health System (Sistema Unico de Saúde, SUS)—the publicly funded health-care system that covers roughly 70% of the hospitalizations and includes information on all admissions (from public hospitals and some private hospitals) authorized for payment by the Unified Health System. The researchers got regional rotavirus vaccination coverage estimates for 2007–2009 from the information department of the Ministry of Health, and estimated coverage of the two doses of oral rotavirus vaccine by taking the annual number of second doses administered divided by the number of infants in the region.
In 2007, an estimated 80% of infants received two doses of rotavirus vaccine, and by 2009, this proportion rose to 84% of children younger than one year of age. The researchers found that in the three years following the introduction of rotavirus vaccination, diarrhea-related mortality rates and admissions among children aged under five years were respectively 22% and 17% lower than expected, with a cumulative total of 1,500 fewer diarrhea deaths and 130,000 fewer admissions. Furthermore, the largest reductions in deaths and admissions were among children who had the highest rates of vaccination (less than two years of age), and the lowest reductions were among children who were not eligible for vaccination during the study period (aged 2–4 years).
What Do These Findings Mean?
These findings suggest that the introduction of rotavirus vaccination in all areas of Brazil is associated with reduced diarrhea-related deaths and hospital admissions in children aged under five years. These real-world impact data are consistent with the clinical trials and strengthen the evidence base for rotavirus vaccination as an effective measure for controlling severe and fatal childhood diarrhea.
These findings have important global policy implications. In middle-income countries, such as Brazil, that are not eligible for financial support from donors, the potential reductions in admissions and other health-care costs will be important for cost-effectiveness considerations to justify the purchase of these still relatively expensive vaccines.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001024
PLoS Medicine has published a series on water and sanitation
More information is available from the World Health Organization on diarrheal illness in children
More information is available about rotavirus vaccines from the World Health Organization, the US Centers for Disease Control and Prevention, and the Rotavirus Vaccine Program
doi:10.1371/journal.pmed.1001024
PMCID: PMC3079643  PMID: 21526228
10.  Incidence and Clinical Characteristics of Group A Rotavirus Infections among Children Admitted to Hospital in Kilifi, Kenya  
PLoS Medicine  2008;5(7):e153.
Background
Rotavirus, predominantly of group A, is a major cause of severe diarrhoea worldwide, with the greatest burden falling on young children living in less-developed countries. Vaccines directed against this virus have shown promise in recent trials, and are undergoing effectiveness evaluation in sub-Saharan Africa. In this region limited childhood data are available on the incidence and clinical characteristics of severe group A rotavirus disease. Advocacy for vaccine intervention and interpretation of effectiveness following implementation will benefit from accurate base-line estimates of the incidence and severity of rotavirus paediatric admissions in relevant populations. The study objective was to accurately define the incidence and severity of group A rotavirus disease in a resource-poor setting necessary to make informed decisions on the need for vaccine prevention.
Methods and Findings
Between 2002 and 2004 we conducted prospective surveillance for group A rotavirus infection at Kilifi District Hospital in coastal Kenya. Children < 13 y of age were eligible as “cases” if admitted with diarrhoea, and “controls” if admitted without diarrhoea. We calculated the incidence of hospital admission with group A rotavirus using data from a demographic surveillance study of 220,000 people in Kilifi District. Of 15,347 childhood admissions 3,296 (22%) had diarrhoea, 2,039 were tested for group A rotavirus antigen and, of these, 588 (29%) were positive. 372 (63%) rotavirus-positive cases were infants. Of 620 controls 19 (3.1%, 95% confidence interval [CI] 1.9–4.7) were rotavirus positive. The annual incidence (per 100,000 children) of rotavirus-positive admissions was 1,431 (95% CI 1,275–1,600) in infants and 478 (437–521) in under-5-y-olds, and highest proximal to the hospital. Compared to children with rotavirus-negative diarrhoea, rotavirus-positive cases were less likely to have coexisting illnesses and more likely to have acidosis (46% versus 17%) and severe electrolyte imbalance except hyponatraemia. In-hospital case fatality was 2% among rotavirus-positive and 9% among rotavirus-negative children.
Conclusions
In Kilifi > 2% of children are admitted to hospital with group A rotavirus diarrhoea in the first 5 y of life. This translates into over 28,000 vaccine-preventable hospitalisations per year across Kenya, and is likely to be a considerable underestimate. Group A rotavirus diarrhoea is associated with acute life-threatening metabolic derangement in otherwise healthy children. Although mortality is low in this clinical research setting this may not be generally true in African hospitals lacking rapid and appropriate management.
Combining prospective hospital-based surveillance with demographic data in Kilifi, Kenya, James Nokes and colleagues assess the burden of rotavirus diarrhea in young children.
Editors' Summary
Background.
Rotavirus is a leading global cause of diarrhea in babies and young children. Indeed, most children become infected at least once with this virus before their fifth birthday. Rotavirus is usually spread by children or their caregivers failing to wash their hands properly after going to the toilet and then contaminating food or drink. The symptoms of rotavirus infection—diarrhea, vomiting, and fever—are usually mild, but if the diarrhea is severe it can quickly lead to dehydration. Mild to moderate dehydration can be treated at home by providing the patient with plenty of fluids or with a special rehydration drink that replaces lost water and salts. However, for infants or toddlers who become severely dehydrated, rehydration with intravenous fluids (fluids injected directly into a vein) in hospital may be essential. Unfortunately, in developing countries in sub-Saharan Africa and elsewhere, this treatment is not widely available and every year more than half a million young children die from rotavirus infections.
Why Was This Study Done?
Two rotavirus vaccines that could reduce this burden of disease are currently undergoing clinical trials to determine their effectiveness in sub-Saharan Africa. However, very little is known about the incidence of severe rotavirus infections among children living in this region (that is, how many children develop severe disease every year) or about the clinical characteristics of the disease here. Public-health officials need this baseline information before they can make informed decisions about the mass introduction of rotavirus vaccination and to help them judge whether the intervention has been successful if it is introduced. In this study, the researchers examine the incidence and clinical characteristics of rotavirus infections (specifically, group A rotavirus [GARV] infections; there are several different rotaviruses but GARV causes most human infections) among children admitted to the district hospital in Kilifi, Kenya.
What Did the Researchers Do and Find?
During the 3-year study, more than 15,000 children under the age of 13 years were admitted to Kilifi District Hospital, a little under a quarter of whom had severe diarrhea. Nearly a third of the patients admitted with diarrhea who were tested had a GARV-specific protein in their stools (faeces); by contrast, only three in 100 children admitted without diarrhea showed any evidence of GARV infection. Two-thirds of the GARV-positive children were infants (under 1 year old). Using these figures and health surveillance data (records of births, deaths, and causes of death) collected in the area around the hospital, the researchers calculated that the annual incidence (per 100,000 children) of GARV-positive hospital admissions in the region was 1,431 for infants and 478 for children under age 5 years. Children with GARV-positive diarrhea were less likely to have other illnesses (for example, malnutrition) than those admitted with GARV-negative diarrhea, the researchers report, but were more likely to have life-threatening complications such as severe dehydration and salt imbalances in their blood. However, despite being more ill on admission, only 1 in 50 children with GARV-positive diarrhea died, compared to nearly 1 in 10 of the children with GARV-negative diarrhea; the GARV-positive children also left hospital quicker than those who were GARV-negative.
What Do These Findings Mean?
These findings indicate that severe GARV-positive diarrhea is a major cause of hospital admission among otherwise healthy young children in the Kilifi region of Kenya. By the time they are 5 years old, the researchers estimate that 1 in 50 of the children living in this region will have been admitted to hospital with severe GARV-positive diarrhea. Because rotavirus vaccines prevent virtually all severe rotavirus-associated disease (at least in developed countries where their effectiveness has been extensively tested), the researchers estimate that vaccination might prevent more than 28,000 hospitalizations annually across Kenya; however, this prediction assumes that it is valid to extrapolate from the data obtained from this one district hospital to the entire country.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050153.
The US Centers for Disease Control and Prevention provides information about rotavirus infections, surveillance, and vaccination (in English and Spanish)
The UK National Health Service Direct health encyclopedia provides information on rotavirus infections
MedlinePlus also provides links to information on rotavirus (in English and Spanish)
The African Rotavirus Surveillance Network is working to improve knowledge about rotavirus infections in Africa
The Rotavirus Vaccine Program aims to reduce child illness and death from diarrhea by increasing the availability of rotavirus vaccines in developing countries (in English and Spanish)
PATH, a nonprofit international organization that aims to create sustainable, culturally relevant solutions to global health problems, also provides detailed information on rotavirus surveillance and disease burden
doi:10.1371/journal.pmed.0050153
PMCID: PMC2488191  PMID: 18651787
11.  Rotavirus Vaccines and Pathogenesis: 2008 
Purpose of Review
Rotaviruses cause life-threatening gastroenteritis in children throughout the world. The burden of disease has resulted in the development of two live, attenuated vaccines that are now licensed in many countries. This review summarizes new data on these vaccines, their effectiveness, and remaining challenges including new data on the rotavirus enterotoxin, a potential antiviral target.
Recent findings
Live attenuated rotavirus vaccines are used to protect infants against severe rotavirus-induced gastroenteritis and, RotaTeq®, a pentavalent bovine based vaccine, and, Rotarix®, a monovalent human rotavirus, are now currently licensed in many countries. Initial results of the licensed RotaTeq® vaccine have been promising in the United States and results of immunogenicity and efficacy in developing countries are expected soon. However universal vaccine implementation is challenging due to age limitations on administration of these vaccines. Chronic rotavirus infections in immunocompromised children may remain a problem and require the development of new treatments including antiviral drugs. Increasing data on the mechanisms of action of the rotavirus enterotoxin highlight this pleiotropic protein as a good target as well as unique calcium agonist.
Summary
Rotavirus is now a commonly occurring vaccine-preventable disease among children in developed countries and hopefully this also will soon be true for developing countries. Future studies will determine if other methods of prevention, such as nonreplicating vaccines and antiviral drugs, will be needed to treat disease in immunocompromised children.
doi:10.1097/MOG.0b013e328317c897
PMCID: PMC2673536  PMID: 19114772
Live; attenuated vaccines; enterotoxin; antivirals; rotavirus
12.  Rotavirus Vaccines: an Overview 
Clinical Microbiology Reviews  2008;21(1):198-208.
Rotavirus infection is the most common cause of severe diarrhea disease in infants and young children worldwide and continues to have a major global impact on childhood morbidity and mortality. Vaccination is the only control measure likely to have a significant impact on the incidence of severe dehydrating rotavirus disease. In 1999, a highly efficacious rotavirus vaccine licensed in the United States, RotaShield, was withdrawn from the market after 14 months because of its association with intussusception. Two new live, oral, attenuated rotavirus vaccines were licensed in 2006: the pentavalent bovine-human reassortant vaccine (RotaTeq) and the monovalent human rotavirus vaccine (Rotarix). Both vaccines have demonstrated very good safety and efficacy profiles in large clinical trials in western industrialized countries and in Latin America. Careful surveillance has not revealed any increased risk of intussusception in the vaccinated groups with either vaccine. The new rotavirus vaccines are now introduced for routine use in a number of industrialized and developing countries. These new safe and effective rotavirus vaccines offer the best hope of reducing the toll of acute rotavirus gastroenteritis in both developed and developing countries.
doi:10.1128/CMR.00029-07
PMCID: PMC2223838  PMID: 18202442
13.  Cost-effectiveness of Rotavirus vaccination in Vietnam 
BMC Public Health  2009;9:29.
Background
Rotavirus is the most common cause of severe diarrhea leading to hospitalization or disease-specific death among young children. New rotavirus vaccines have recently been approved. Some previous studies have provided broad qualitative insights into the health and economic consequences of introducing the vaccines into low-income countries, representing several features of rotavirus infection, such as varying degrees of severity and age-dependency of clinical manifestation, in their model-based analyses. We extend this work to reflect additional features of rotavirus (e.g., the possibility of reinfection and varying degrees of partial immunity conferred by natural infection), and assess the influence of the features on the cost-effectiveness of rotavirus vaccination.
Methods
We developed a Markov model that reflects key features of rotavirus infection, using the most recent data available. We applied the model to the 2004 Vietnamese birth cohort and re-evaluated the cost-effectiveness (2004 US dollars per disability-adjusted life year [DALY]) of rotavirus vaccination (Rotarix®) compared to no vaccination, from both societal and health care system perspectives. We conducted univariate sensitivity analyses and also performed a probabilistic sensitivity analysis, based on Monte Carlo simulations drawing parameter values from the distributions assigned to key uncertain parameters.
Results
Rotavirus vaccination would not completely protect young children against rotavirus infection due to the partial nature of vaccine immunity, but would effectively reduce severe cases of rotavirus gastroenteritis (outpatient visits, hospitalizations, or deaths) by about 67% over the first 5 years of life. Under base-case assumptions (94% coverage and $5 per dose), the incremental cost per DALY averted from vaccination compared to no vaccination would be $540 from the societal perspective and $550 from the health care system perspective.
Conclusion
Introducing rotavirus vaccines would be a cost-effective public health intervention in Vietnam. However, given the uncertainty about vaccine efficacy and potential changes in rotavirus epidemiology in local settings, further clinical research and re-evaluation of rotavirus vaccination programs may be necessary as new information emerges.
doi:10.1186/1471-2458-9-29
PMCID: PMC2663769  PMID: 19159483
14.  The molecular epidemiology of circulating rotaviruses: three-year surveillance in the region of Monastir, Tunisia 
BMC Infectious Diseases  2011;11:266.
Background
Rotavirus infection is the most common cause of severe, dehydrating, gastroenteritis among children worldwide. In developing countries, approximately 1440 children die from rotavirus infections each day, with an estimated 527,000 annually. In infants, rotavirus is estimated to cause more than 2 million hospitalizations every year depending on the income level of the country.
The purpose of this study was to estimate the proportion of rotavirus gastroenteritis and identify the distribution of circulating G and P genotype rotavirus strains among children consulting several dispensaries in the region of Monastir (outpatients departments) or admitted to Monastir University Hospital (inpatients department) with acute gastroenteritis.
Methods
This study was undertaken during a 3-year period from April 2007 to April 2010 in Tunisian children under 13 suffering from acute gastroenteritis. Group A rotaviruses were detected in stools by ELISA and genotyped using multiplex reverse transcription PCRs with type-specific primers on the basis of their outer capsid proteins. Statistical analyses were performed with SPSS software, version 19.
Results
Of the 435 stool samples from children with acute gastroenteritis, 27.6% were positive for rotavirus A. The predominant G type was G1 (37.5%), followed by G3 (25%), G2 (17.5%), G4 (12.5%), G9 (2.5%) and three mixed-G infections G3G4 (2.5%) were identified.
Only P[8] (80.8%), P[4] (16.7%) and P[9] (0.8%) genotypes were found. The predominant single G/P combination was G1P[8] (37.5%), followed by G3P[8] (25%), G2P[4] (16.7%), G4P[8] (12.5%), G9P[8] (1.7%) and one case of the unusual combination G9P[9] (0.8%). The G-mixed types G3G4 combined with P[8] (2.5%). Infants less than 3 months of age were most frequently affected. The prevalence of rotavirus infection peaked in the winter season, when temperatures were low, and decreased in summer.
Conclusions
Rotavirus gastroenteritis is a common disease associated with significant morbidity, mortality, and economic burden. Epidemiological knowledge of rotavirus is critical for the development of effective preventive measures, including vaccines.
These data will help to make informed decisions as to whether rotavirus vaccine should be considered for inclusion in Tunisia's National Immunisation Programme.
doi:10.1186/1471-2334-11-266
PMCID: PMC3193173  PMID: 21967503
15.  Early exposure of infants to natural rotavirus infection: a review of studies with human rotavirus vaccine RIX4414 
BMC Pediatrics  2014;14(1):295.
Background
Rotaviruses are the leading cause of severe acute gastroenteritis in children aged <5 years worldwide. A live attenuated human rotavirus vaccine, RIX4414 has been developed to reduce the global disease burden associated with rotavirus gastroenteritis. Serum anti-rotavirus immunoglobulin A (IgA) antibody measured in unvaccinated infants during clinical trials of RIX4414 reflects natural rotavirus exposure, and may inform the optimal timing for rotavirus vaccination.
Methods
We reviewed phase II and III randomized, placebo-controlled clinical trials conducted by GlaxoSmithKline Vaccines, Wavre, Belgium between 2000 and 2008 which used the commercial formulation of RIX4414 lyophilized vaccine. We included trials for which demographic data and pre-dose-1 and post-last-dose anti-rotavirus IgA antibody status were available from placebo recipients.
Results
Sixteen clinical trials met the inclusion criteria. The studies were conducted across Africa (N = 3), Asia (N = 4), Latin America (N = 4), Europe (N = 4) and North America (N = 1). Overall, 46,398 infants were enrolled and among these, 20,099 received placebo. The mean age at pre-dose-1 time point ranged from 6.4 − 12.2 weeks while the mean age at post-last-dose time point ranged from 13.5 − 19.6 weeks. The anti-RV IgA seropositivity rates at both time points were higher in less developed countries of Africa, Asia and Latin America (pre-dose-1: 2.1%-26.3%; post-last-dose: 6.3%-34.8%) when compared to more developed countries of Asia, Europe and North America (pre-dose-1: 0%-9.4%; post-last-dose: 0%-21.3%), indicating that rotavirus infections occurred at a younger age in these regions.
Conclusion
Exposure to rotavirus infection occurred early in life among infants in most geographical settings, especially in developing countries. These data emphasize the importance of timely rotavirus vaccination within the Expanded Program on Immunization schedule to maximize protection.
doi:10.1186/s12887-014-0295-2
PMCID: PMC4261882  PMID: 25433534
Rotavirus; Early protection; Gastroenteritis; Anti-rotavirus
16.  Compliance of mothers following recommendations to breastfeed or withhold breast milk during rotavirus vaccination in North India: a randomized clinical trial 
Trials  2014;15:256.
Background
Neutralizing antibodies in breast milk may adversely influence the immune response to live oral vaccines. Withholding breastfeeding around the time of vaccine administration has been suggested for improving vaccine performance. However, we do not know whether mothers find withholding breastfeeding around the time of vaccination acceptable and how they perceive this recommendation.
Methods
In a clinical study designed to examine predictors of poor immune response to rotavirus vaccine in infants in India, Rotarix® was administered to infants at 6 and 10 weeks with other childhood vaccines. For the study, 400 mother–infant pairs were randomized into two groups in a 1:1 ratio. Mothers were either recommended to withhold breastfeeding or were encouraged to breastfeed half an hour before and after administration of Rotarix®. The mother–infant pairs were observed and the breastfeeding intervals were recorded during this period. Mothers were administered a questionnaire about their perception of the intervention after the infants received the second dose of Rotarix®.
Results
Almost 98% (391/400) of the infants received both doses of Rotarix®. Adherence to the recommendations was high in both groups. All mothers in the group who were asked to withhold breastfeeding did so, except one who breastfed her infant before the recommended time after the first dose of Rotarix®. Of the mothers, 4% (7/195) reported that the recommendation to withhold breastfeeding was difficult to follow. All mothers in this group reported that they would withhold breastfeeding at the time of vaccination if they were asked to by a health-care provider. Only one mother responded that withholding breastfeeding would be a reason for not giving rotavirus vaccine to her infant.
Conclusions
Withholding breastfeeding half an hour before and after vaccination appears to be acceptable to mothers in this setting. If withholding breastfeeding produces an improvement in the performance of the vaccine, it could be used to increase the public health impact of rotavirus immunization.
Trial registration
Clinical Trial Registry, India (CTRI/2012/10/003057), Clinicaltrials.gov (NCT01700127).
Date of Registration: Clinical Trial Registry, India: 28 September 2012, Clinicaltrials.gov: 3 October 2012.
doi:10.1186/1745-6215-15-256
PMCID: PMC4082496  PMID: 24976452
rotavirus; Rotarix®; withhold breastfeeding; encourage breastfeeding; perception
17.  Will vaccination against rotavirus infection with RIX4414 be cost-saving in Germany? 
Background
Rotavirus gastroenteritis (RVGE) is a frequent disease in young children. The recommended German paediatric immunisation schedule does not currently include rotavirus vaccination. A lack of economic data on the impact of routine vaccination is stated as one of the reasons. As a result, the current coverage rate is low, around 26%. This study investigated whether rotavirus vaccination using the two-dose rotavirus vaccine RIX4414 (Rotarix®, GlaxoSmithKline Vaccines) would be a cost-saving intervention from the perspective of the statutory health insurance (SHI) in Germany.
Objective
The objective of the study was to analyse health outcomes (number of RVGE cases and hospitalisations prevented) and the associated cost to the SHI when comparing 100% rotavirus vaccination with no vaccination in Germany.
Methods
A Markov cohort model simulated the number of RVGE events and related costs in a German birth cohort over the first 60 months of life with current disease management. The model compared an unvaccinated cohort with a fully vaccinated cohort. Vaccine efficacy data from international clinical trials were combined with German-specific epidemiological and cost data. Results were tested using extensive sensitivity analyses.
Results
Full vaccination of a birth cohort against rotavirus disease would be expected to prevent 82% of RVGE cases, reducing RVGE frequency from 28 to 5 events per 100 children in the birth cohort up to age 5 years. The estimated cost reduction with vaccination for that period is predicted to be €9.2 million with 100% coverage (€6.9 million with 75% coverage), mainly due to reductions in SHI reimbursement for productivity losses, hospital stays and visits to office-based physicians due to the vaccine’s efficacy against severe disease.
Conclusions
Routine rotavirus vaccination in Germany would reduce the number of hospitalised and outpatient cases. The associated investment could be fully offset by costs avoided in hospital stays, physician visits and SHI reimbursement of productivity losses. Sensitivity analysis indicated that vaccination would be cost-saving in 95% of simulations. Incremental cost was observed only under extreme conditions, especially when the time spent at home due to rotavirus disease was low or when vaccine efficacy against severe disease was heavily decreased.
doi:10.1186/2191-1991-3-27
PMCID: PMC3831585  PMID: 24246029
Cost savings; Economic evaluation; Germany; Paediatric; RIX4414; Rotavirus; Vaccination
18.  Efficacy and safety of pentavalent rotavirus vaccine in Japan 
Human Vaccines & Immunotherapeutics  2013;9(8):1626-1633.
Rotavirus is the most common cause of severe gastroenteritis in children under 5 y of age. Estimates of disease burden in Japan suggest that between 26,500 and 78,000 children in this age group need hospitalization each year, resulting in a direct medical cost of 10 to 24 billion Yen. Since being introduced in routine infant immunization schedules in the United States in 2006, the oral live pentavalent rotavirus vaccine RV5 (RotaTeq™) has contributed to dramatic reductions in the incidence of rotavirus gastroenteritis (RVGE) and in health care resource utilization. This was a multicenter, randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy and safety of a 3-dose regimen of RV5 in healthy infants, age 6 to 12 weeks, at 32 sites across Japan. The results indicate that RV5 was significantly efficacious in preventing any severity [74.5% (95% confidence interval [CI]: 39.9%, 90.6%; p < 0.001)], moderate-to-severe [80.2% (95% CI: 47.4%, 94.1%)], and severe [100% (95% CI: 55.4%, 100%)] RVGE caused by viruses with serotypes contained in the vaccine. The observed cases of RVGE included rotavirus types G1 (n = 19), G3 (n = 9), G9 (n = 5) and one unspecified G serotype with P1A[8]. No G2 or G4 RVGE cases were observed, and this study was not powered to evaluate efficacy against individual serotypes. RV5 was generally safe and well tolerated in Japanese infants. These results are comparable to those observed in clinical studies conducted in other developed countries. Introduction of the vaccine in Japan may reduce disease burden and associated health care costs.
doi:10.4161/hv.24846
PMCID: PMC3906258  PMID: 23732903
rotavirus gastroenteritis; RVGE; vaccine; pentavalent rotavirus vaccine; RV5
19.  Genetic Diversity of Circulating Rotavirus Strains in Tanzania Prior to the Introduction of Vaccination 
PLoS ONE  2014;9(5):e97562.
Background
Tanzania currently rolls out vaccination against rotavirus-diarrhea, a major cause of child illness and death. As the vaccine covers a limited number of rotavirus variants, this study describes the molecular epidemiology of rotavirus among children under two years in Dar es Salaam, Tanzania, prior to implementation of vaccination.
Methods
Stool specimens, demographic and clinical information, were collected from 690 children admitted to hospital due to diarrhea (cases) and 545 children without diarrhea (controls) during one year. Controls were inpatient or children attending child health clinics. Rotavirus antigen was detected using ELISA and positive samples were typed by multiplex semi-nested PCR and sequencing.
Results
The prevalence of rotavirus was higher in cases (32.5%) than in controls (7.7%, P<0.001). The most common G genotypes were G1 followed by G8, G12, and G4 in cases and G1, G12 and G8 in controls. The Tanzanian G1 variants displayed 94% similarity with the Rotarix vaccine G1 variant. The commonest P genotypes were P[8], P[4] and P[6], and the commonest G/P combination G1 P[8] (n = 123), G8 P[4] and G12 P[6]. Overall, rotavirus prevalence was higher in cool (23.9%) than hot months (17.1%) of the year (P = 0.012). We also observed significant seasonal variation of G genotypes. Rotavirus was most frequently found in the age group of four to six months. The prevalence of rotavirus in cases was lower in stunted children (28.9%) than in non-stunted children (40.1%, P = 0.003) and lower in HIV-infected (15.4%, 4/26) than in HIV-uninfected children (55.3%, 42/76, P<0.001).
Conclusion
This pre-vaccination study shows predominance of genotype G1 in Tanzania, which is phylogenetically distantly related to the vaccine strains. We confirm the emergence of genotype G8 and G12. Rotavirus infection and circulating genotypes showed seasonal variation. This study also suggests that rotavirus may not be an opportunistic pathogen in children infected with HIV.
doi:10.1371/journal.pone.0097562
PMCID: PMC4028215  PMID: 24844631
20.  Epidemiology and Genetic Diversity of Rotavirus Strains in Children with Acute Gastroenteritis in Lahore, Pakistan 
PLoS ONE  2013;8(6):e67998.
Pakistan harbors high disease burden of gastro-enteric infections with majority of these caused by rotavirus. Unfortunately, lack of proper surveillance programs and laboratory facilities have resulted in scarcity of available data on rotavirus associated disease burden and epidemiological information in the country. We investigated 1306 stool samples collected over two years (2008–2009) from hospitalized children under 5 years of age for the presence of rotavirus strains and its genotypic diversity in Lahore. The prevalence rate during 2008 and 2009 was found to be 34% (n = 447 out of 1306). No significant difference was found between different age groups positive for rotavirus (p>0.05). A subset of EIA positive samples was further screened for rotavirus RNA through RT-PCR and 44 (49.43%) samples, out of total 89 EIA positive samples, were found positive. G and P type prevalence was found as follows: G1P [4] = 3(6.81%); G1P [6] = 9(20.45%); G1P [8] = 1(2.27%); G2P [4] = 21(47.72%); G2P [8] = 1(2.27%); G9P [4] = 1(2.27%); G9P [6] = 1(2.27%) and G9P [8] = 7(15.90%). Phylogenetic analysis revealed that the VP7 and VP4 sequences clustered closely with the previously detected strains in the country as well as Belgian rotaviruses. Antigenic characterization was performed by analyzing major epitopes in the immunodominant VP7 and VP4 gene segments. Although the neutralization conferring motifs were found variable between the Pakistani strains and the two recommended vaccines strains (Rotarix™ and RotaTeq™), we validate the use of rotavirus vaccine in Pakistan based on the proven and recognized vaccine efficacy across the globe. Our findings constitute the first report on rotavirus’ genotype diversity, their phylogenetic relatedness and epidemiology during the pre-vaccination era in Lahore, Pakistan and support the immediate introduction of rotavirus vaccine in the routine immunization program of the country.
doi:10.1371/journal.pone.0067998
PMCID: PMC3692488  PMID: 23825693
21.  Investigation of a regulatory agency enquiry into potential porcine circovirus type 1 contamination of the human rotavirus vaccine, Rotarix™ 
Human Vaccines & Immunotherapeutics  2013;9(11):2398-2408.
In January 2010, porcine circovirus type 1 (PCV1) DNA was unexpectedly detected in the oral live-attenuated human rotavirus vaccine, Rotarix™ (GlaxoSmithKline [GSK] Vaccines) by an academic research team investigating a novel, highly sensitive analysis not routinely used for adventitious agent screening. GSK rapidly initiated an investigation to confirm the source, nature and amount of PCV1 in the vaccine manufacturing process and to assess potential clinical implications of this finding. The investigation also considered the manufacturer’s inactivated poliovirus (IPV)-containing vaccines, since poliovirus vaccine strains are propagated using the same cell line as the rotavirus vaccine strain. Results confirmed the presence of PCV1 DNA and low levels of PCV1 viral particles at all stages of the Rotarix™ manufacturing process. PCV type 2 DNA was not detected at any stage. When tested in human cell lines, productive PCV1 infection was not observed. There was no immunological or clinical evidence of PCV1 infection in infants who had received Rotarix™ in clinical trials. PCV1 DNA was not detected in the IPV-containing vaccine manufacturing process beyond the purification stage. Retrospective testing confirmed the presence of PCV1 DNA in Rotarix™ since the initial stages of its development and in vaccine lots used in clinical studies conducted pre- and post-licensure. The acceptable safety profile observed in clinical trials of Rotarix™ therefore reflects exposure to PCV1 DNA. The investigation into the presence of PCV1 in Rotarix™ could serve as a model for risk assessment in the event of new technologies identifying adventitious agents in the manufacturing of other vaccines and biological products.
doi:10.4161/hv.25973
PMCID: PMC3981850  PMID: 24056737
Rotarix™; adventitious agents; human rotavirus vaccine; inactivated poliovirus vaccine; porcine circovirus type 1
22.  Performance of rotavirus vaccines in developed and developing countries 
Human Vaccines  2010;6(7):532-542.
The World Health Organization estimates that rotavirus diarrhea results in approximately half a million deaths and approximately 2.4 million hospitalizations in developing countries each year. Two live oral rotavirus vaccines, RotaTeq® (RV 5; Merck) and Rotarix® (RV 1; GlaxoSmithKline) with good efficacy against severe rotavirus disease and a reassuring safety profile could substantially impact the burden of rotavirus disease. In April 2009, WHO provided a recommendation for global introduction of these vaccines in national immunization programs of developing countries worldwide. In this article, we review published data on previous candidate rotavirus vaccines and vaccines in current use, with emphasis on their performance in developed versus developing countries. In developed countries, both first and second generation rotavirus vaccines have demonstrated high efficacy against severe rotavirus disease (pooled efficacy = 73% and 85%, respectively). In developing countries, small early trials for the first generation vaccines failed to provide protection against rotavirus disease (pooled efficacy = 20%), however, trials of the second generation vaccines yielded substantial improvements in efficacy in developing countries (pooled efficacy of 51%), leading to a global recommendation for rotavirus vaccine introduction by WHO. Future efforts for these vaccines should focus on optimizing the efficacy and delivery of these vaccines in challenging target populations of Asia and Africa with the greatest burden of severe rotavirus disease.
doi:10.4161/hv.6.7.11278
PMCID: PMC3322519  PMID: 20622508
rotavirus; vaccines; immunization; vaccination; diarrhea; gastroenteritis
23.  Burden and Typing of Rotavirus Group A in Children with Acute Gastroenteritis in Shiraz, Southern Iran 
Background
Human Rotavirus is a significant cause of severe gastroenteritis in infants and young children worldwide. In recent years, Rotavirus genotyping by RT-PCR has provided valuable information about the diversity of Rotaviruses circulating worldwide. The purpose of the present study is to monitor the prevalence of the different G types of Rotaviruses circulating in Shiraz, Southern Iran and detect any uncommon or novel types.
Methods
During the period from December 2007 to November 2008, a total of 138 stool samples were collected from children less than 5 years old who were hospitalized for acute gastroenteritis. Rotavirus-associated diarrhea was investigated in fecal specimens with enzyme immunoassays (EIA). Rotavirus-positive specimens were typed by the Nested RT-PCR and by using different types of specific primers.
Results
Out of the 138 collected samples, 34.78% (48 cases) tested positive for Rotavirus. The frequency of G1, G2 and G4 types was 6.25%, 2.08% and 27.08%, respectively. Mixed and non-typeable infections were detected in 33.34% and 31.25% of hospitalized children with acute diarrhea, respectively. This is the first time mixed Rotavirus infections with G1/G3 have been reported in Iran.
Conclusion
The high frequency of Rotavirus detection indicates the severity and the burden of Rotavirus disease may be able to reduce through the implementation of an effective vaccine and continual surveillance for the detection of Rotavirus genotypes circulating in other regions of Iran.
Regarding to the noticeable frequency of non-typeable and mixed infections, it is suggested to use the other specific primers and further studies to detection of other novel and unusual types.
PMCID: PMC3482325  PMID: 23115715
Human Rotavirus; Diarrhea; Hospitalized children; G types
24.  Prevalence and Molecular Genotyping of Group A Rotaviruses in Iranian Children 
Rotavirus is the leading cause of acute gastroenteritis in worldwide young children. Effective vaccines to prevent rotavirus infection are currently available, although their clinical use is still limited, and rotavirus still causes many episodes of infantile gastroenteritis, mainly during the winter season. The aim of this study was to evaluate the prevalence of rotavirus infection in children aged <5-years-old who were hospitalised for gastroenteritis. One hundred and sixty-three stool samples from hospitalised children (<5-years-old) complicated with severe diarrhoea, in two hospitals in Jahrom City, Iran were collected from 2009 to 2010. Antigenic prevalence of rotavirus group A was distinguished by enzyme immunoassay. The antigen of group A rotavirus was diagnosed by EIA in 75 of 163 collected samples. The genotype of EIA-positive samples was determined by nested RT-PCR. The frequency of rotavirus genotypes G1, G2, G3, G4 and G9 was 17.33, 13.34, 2.67, 30.66 and 2.67 %, respectively. Also, the frequency of mixed and non-typable genotypes was detected in 2.67 and 30.66 %, respectively. G1/G8 mixed infection was the first of these rotavirus genotypes to be reported in Iran. Detection of high prevalence of group A rotavirus infection in hospitalised children with diarrhoea, and determination of circulating rotavirus genotypes in this region of Iran, provide useful data for formulating effective vaccines; especially for infants less than 5-years-old.
doi:10.1007/s13337-012-0070-7
PMCID: PMC3550810  PMID: 23729998
Rotavirus; Prevalence; Molecular genotyping; RT-PCR
25.  Novel Rotavirus VP7 Typing Assay Using a One-Step Reverse Transcriptase PCR Protocol and Product Sequencing and Utility of the Assay for Epidemiological Studies and Strain Characterization, Including Serotype Subgroup Analysis 
Journal of Clinical Microbiology  2005;43(12):5876-5880.
Rotavirus is the most common cause of severe dehydrating gastroenteritis in infants. To date, 10 different serotypes of rotavirus have been identified in human stools. While four or five serotypes dominate, serotype circulation varies with season and geography. Since our laboratory has been involved in the development of a multivalent rotavirus vaccine, it is important to identify the serotypes of rotavirus encountered during our clinical trials. We have developed methodologies for the molecular identification of rotavirus strains based on VP7 gene segment sequence. A 365-bp reverse transcriptase PCR product was generated from the VP7 gene segment using a pair of novel degenerate primers. All serotypes tested (both animal and human) yielded an identically sized product after amplification. Sequencing of these products is performed using truncated versions of the original primers. The sequence generated is compared against a database of rotavirus VP7 sequences, with the G type determined, based on the sequence homology. Using this assay, we have correctly identified human VP7 strains from a panel of available serotypes, as well as numerous animal strains. The assay was qualified using rotavirus positive stool samples, negative stool samples, and rotavirus-spiked stool samples. In addition, samples from cases of acute gastroenteritis collected at Children's Hospital of Philadelphia have been evaluated and indicate that the assay is able to discriminate subtle differences within serotypes. The assay has been utilized in the testing of >3,000 antigen-positive (enzyme immunoassay) samples collected during clinical trials of a rotavirus vaccine (RotaTeq) and identified a serotype in ∼92% of samples (3, 17, 19).
doi:10.1128/JCM.43.12.5876-5880.2005
PMCID: PMC1317171  PMID: 16333070

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