Burden of rotavirus in India - Is rotavirus vaccine an answer to it?

Abstract

Rotavirus is currently by far the most common cause of severe diarrhea in infants and young children worldwide and of diarrheal deaths in developing countries. Worldwide Rotavirus is responsible for 611,000 childhood deaths out of which more than 80% occur in low-income countries. The resistance of rotavirus to commonly used disinfectants and ineffectiveness of oral rehydration therapy due to severe vomiting indicates that if an effective vaccine is the preferred option. WHO has recommended inclusion of rotavirus vaccine in the National Schedules where under 5 mortality due to diarrheal diseases is ≥ 10%. Currently two vaccines are available against rotavirus. Rotarix (GlaxoSmithKline) is a monovalent vaccine recommended to be orally administered in two doses at 6-12 weeks. Rota Teq (Merck) is a pentavalent vaccine recommended to be orally administered in three doses starting at 6-12 weeks of age. Serodiversity of rotavirus in India and its regional variation favor either a monovalent vaccine that can induce heterotypic immunity or a polyvalent vaccine incorporating majority of serotypes prevalent in the country. However, the efficacy of available rotavirus vaccines is less in low-income countries. Both the candidate vaccines when coadministered with OPV, immune response to first dose of these vaccines is reduced. However, immune responses to subsequent rotavirus vaccine doses are not affected. In view of this, WHO recommends three doses of either vaccine to be given to children in developing countries to produce the optimum response. Indigenous vaccine, 116E (Bharat Biotech) based on human rotavirus of serotype G9P [11] is still under Phase 2 trials. Another multivalent vaccine is being developed by Shantha Biotechnics in India. The cost effectiveness of the three dose schedule of the available and the rsults of the field trials of the indigenous vaccines should be assessed before inclusion of rotavirus vaccine in the National Immunization Schedule.