• rotavirus
• vaccination
• intussusception

By the age of five years, between 1 in 40 and 1 in 77 children in Europe and the USA will have been hospitalised for rotavirus diarrhoea.¹ Although health care and economic costs of the illness are high, mortality in developed countries is very low. In contrast with the developing world, and despite considerable efforts to educate carers in simple oral rehydration therapy, it is estimated that 600 000–800 000 children, or 1 in 40 children in the first five years of life, die annually from rotavirus infection.² The advantages of an oral rotavirus vaccine thus seem self evident: economic benefits to the developed world and significantly reduced infant mortality in the developing world. Candidate rotavirus vaccines were first developed by tissue culture adaptation and attenuation of bovine and rhesus rotaviruses. Subsequently, such heterologous rotaviruses were improved for use as human vaccines by reassortment with human rotaviruses. After favourable results of prelicensing trials in the USA and Finland^3–6 showing vaccine efficacies of 68% and 91% for reduction of all and serious rotavirus infections, respectively, the US food and drug administration licensed an oral tetravalent rhesus-human reassortant rotavirus vaccine (RRV-TV) in August 1998. Distribution of the vaccine for incorporation into infant schedules commenced in the USA in October 1998. By the end of May 1999, when approximately 1.5 million doses of RRV-TV vaccine had been distributed, nine cases of intussusception in infants …