Thousands of children in developing countries die each year from diarrhoea caused by rotavirus. Shortly after RotaShield — a vaccine against the virus — was launched in the late 1990s, it was discovered that the vaccine could lead to a potentially fatal bowel disorder called intussusception. Though the risk was considered low enough to warrant use of the vaccine in the developing world where rotavirus infects 1 in 200 children, it was deemed too high for use in the United States, and production was halted.
In this article, Leslie Roberts describes renewed attempts to create a live oral vaccine. GlaxoSmithKline Biologicals and Merck are the two pharmaceutical players involved and their studies on candidate vaccines, Rotarix and RotaTeq, have the full backing of the Global Alliance for Vaccines and Immunisation.
Although early results are promising, this second attempt is unlikely to be all plain sailing. The diversity of rotavirus varieties could make protection against all or even most strains impossible. Also, clinical trials have not been run in countries in Africa and Asia, which are hit hardest by the disease. If successful, says Roberts, this enterprise could become a model for vaccines against malaria and HIV. If it fails, however, it's back to the drawing board, which means a long wait for poorer nations.
Reference: Science 305, 1890 (2004)