Rotavirus vaccines against diarrhoeal disease.

Rotaviruses are responsible for more diarrhoeal disease-associated mortality than any other single agent. Vaccination may therefore hold the key to combating diarrhoeal disease worldwide. Natural immunity to rotavirus infection indicates that rather than protection from reinfection such immunity gives rise to less severe and less frequent attacks of diarrhoea. Early attempts to design a rotavirus vaccine with bovine rotavirus failed because of poor efficacy in some developing countries. Research into rhesus rotavirus, particularly the high-titre rhesus rotavirus tetravalent (RRV-TV) vaccine, has given slightly better results. A stumbling block to truly effective oral vaccines seems to be immunogenicity in developing countries. If efficacy can be ensured by trials in the developing countries, money spent on rotavirus vaccines will be well spent.