Special Section Future Trendsin Vaccination: Rotavirus vaccines: development and use for the prevention of diarrhoeal disease

Rotavirus causes annually 600 000 deaths of young children worldwide, mainly in developing countries. The burden of rotavirus disease is significant also in developed countries and has not diminished with improved hygiene. Natural protective immunity against severe rotavirus disease is built up during the first 2-3 years of life. Likewise, studies with live attenuated oral rotavirus vaccines have shown that the majority of severe episodes of rotavirus diarrhoea are preventable by oral immunization. Candidate rotavirus vaccines were first developed by tissue culture adaptation and attenuation of bovine and rhesus rotaviruses, both of which share the inner core VP6 group antigen with human group A rotaviruses. Subsequently, such heterologous rotaviruses were improved for use as human vaccines by reassortment with human rotaviruses; the resulting reassortants express human rotavirus VP7 surface antigens. A rhesus-human reassortant tetravalent (RRV-TV) rotavirus vaccine was licensed in the USA in 1998, and is recommended for universal immunization of healthy children; licensure in Europe is also imminent. In Finland, this vaccine has prevented 90% of severe episodes of rotavirus gastroenteritis. Protective efficacy of RRV-TV vaccine in developing countries is lower and a more intensive immunization schedule may be needed. Several other candidate rotavirus vaccines, including bovine-human reassortants, are being investigated.