Merck & Co’s Rotateq vaccine against rotavirus infection won an important endorsement yesterday after a US Centers for Disease Control advisory committee voted to include it in routine infant vaccination schedules.

Rotateq was cleared by the US Food and Drug Administration (FDA) earlier this month, and represents the first rotavirus vaccine to be available since 1999, when Wyeth's RotaShield was removed from the market after being linked to a severe twisting of the bowel known as intussusception.

The Advisory Committee on Immunization Practices (ACIP) backed its use in national immunisation programmes, but cautioned that the vaccine should only be used in infants, who are believed to have a smaller risk of developing intussusception than older children. It stressed this was a precautionary measure - Rotateq was not associated with an increase in this side effect in clinical trials involving 72,000 children.

Rotateq is given in three oral doses at two, four and six months of age.

The recommendation makes it more likely that Rotateq will meet its commercial expectations, with some analysts predicting that sales of the vaccine could top $500 million a year at peak.

Rotavirus causes around 55,000 young children to be hospitalised each year in the USA and, while rarely fatal in developed countries, is a major killer of children in the developing world.

A rival vaccine, GlaxoSmithKline’s Rotarix, has already reached the market elsewhere but is not yet available in the USA. This vaccine can be delivered in two doses one to two months apart.