Routine rotavirus vaccination in Brazil has reduced diarrheoa deaths in children
Wednesday, April 20th, 2011
Diarrhoeal disease, usually caused by infectious agents, is the second major cause of death in children aged under five years. 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 diarrhoea, 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.
Rotavirus vaccination in all areas of Brazil is associated with reduced diarrheoa-related deaths and hospital admissions in children aged under five years. New research has shown that these real-world impact data – what actually happens in reality rather than in strictly controlled clinical trial settings – are consistent with the clinical trials and conclude that their study strengthens the evidence base for use of rotavirus vaccination as an effective measure for controlling severe and fatal childhood diarrheoa.
Brazil has a high incidence of diarrhea-related deaths and hospital admissions in young children and, in July 2006, the Brazilian Ministry of Health introduced rotavirus vaccination simultaneously in all 27 states, allowing the authors to conduct a ‘‘before’’ and ‘‘after’’ intervention analysis. Using routinely collected national data, the authors found that in 2007 an estimated 80% of infants received two doses of rotavirus vaccine, and by 2009 that this proportion rose to 84% of children younger than one year of age. 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 diarrheoa deaths and 130,000 fewer hospital 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 age-eligible for vaccination during the study period (aged 2–4 years).
This time-series analysis provides evidence of substantial reductions following the introduction of rotavirus vaccination of both diarrheoa-related deaths and diarrheoa-related hospital admissions from a large middle-income country in the Americas with both developing and developed regions. In middle-income countries that are not eligible for financial support from donors, the potential reductions in diarrheoa-related hospital admissions and other health-care costs will be important for cost-effectiveness considerations to justify the purchase of these relatively expensive vaccines.
Decline in Diarrhea Mortality and Admissions after Routine Childhood Rotavirus Immunization in Brazil: A Time-Series Analysis. 2011 PLoS Med 8(4): e1001024. doi:10.1371/journal.pmed.1001024
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.
