For the first time ever, studies in Mexico and Africa, published today in the New England Journal of Medicine, demonstrate a reduction in diarrheal disease deaths following rotavirus vaccine introduction in Mexico and vaccine efficacy among impoverished populations in Malawi and South Africa. Both studies underscore the importance of vaccination in achieving significant reduction of severe rotavirus infections among children in the developing world, where disease impact is greatest. Worldwide, rotavirus is the leading cause of severe diarrhea, which takes the lives of more than 500,000 children under 5 every year – with almost half of these deaths occurring in Africa – and causes the hospitalization of millions more.

The findings from these studies informed the World Health Organization’s (WHO) recent recommendation that rotavirus vaccines be included in every nation’s immunization program. The recommendation is important for Africa which is hit particularly hard by the disease and places rotavirus vaccines among a comprehensive set of other interventions key to stopping diarrheal disease deaths, including access to clean water, proper sanitation and oral rehydration therapies (ORT), breastfeeding, and vitamin A and zinc supplementation.

In an editorial accompanying the studies’ results, Mathuram Santosham, Professor of International Health and Pediatrics at Johns Hopkins University, Baltimore, welcomed these studies for supporting the use of rotavirus vaccines in the poorest countries of the world. “We now have another powerful weapon to add to our armamentarium to combat diarrheal deaths – rotavirus vaccines,” wrote Santosham. “Rotavirus vaccine should be introduced immediately in high mortality areas and it should be used as a trigger to energize diarrhea control programs and improve coverage for all the proven interventions for diarrhea.”

In Mexico, which in 2006 was among the first countries in the world to introduce rotavirus vaccine, diarrheal disease death rates dropped during the 2009 rotavirus season by more than 65 percent among children age two and under. This demonstrates real-world impact that is crucial as other countries consider rotavirus vaccine introduction. The Mexico study examined the impact of vaccination on diarrheal deaths in Mexican children between 2008 and 2009 following a phased introduction of the orally administered RotarixRotarixTM, manufactured by GlaxoSmithKline Biologicals (GSK).