Officials at the Food and Drug Administration (FDA) advised physicians Monday to temporarily stop using Rotarix, a vaccine commonly given to children to protect them against the stomach bug rotavirus, because it is contaminated with traces of a second virus. The contaminant, called PCV-1, is a DNA virus that infects pigs and other species but is not known to cause illness in humans or any other animals. The virus appears to have come from the cell cultures used to make Rotarix. "There is no evidence this poses a safety risk," said Margaret A. Hamburg The contaminant was found by a team of independent researchers testing a new way to screen vaccines for impurities. Rotarix's maker, the pharmaceutical company GlaxoSmithKline, was told of the finding in early February. Both it and the FDA have since confirmed the presence of PCV-1 in the vaccine, which is given in two oral doses to infants between 6 and 24 weeks old. Hamburg said the FDA is not pulling Rotarix off the market, and that even asking doctors to suspend its use for the moment "was not an easy call." After consulting with scientists at the National Institutes of Health and the Centers for Disease Control and Prevention, as well as officials at the Department of Health and Human Services, "We felt that the judicious thing to do was to make a pause and try to determine what this virus was doing in the vaccine and how it got there." Rotavirus can cause vomiting and watery diarrhea in infants and children. Globally, it is one of the more serious infections of infancy, causing about 500,000 deaths a year. While deaths number fewer than 100 in the United States, the virus was responsible for about 50,000 pediatric hospitalizations annually before the vaccine came into common use. Rotarix was licensed in 2008. Another rotavirus vaccine, RotaTeq, made by Merck, came on the market in 2006. FDA officials suggested that pediatricians use it rather than Rotarix for the time being. Although the FDA is recommending that doctors avoid Rotarix, Hamburg said she realizes health agencies in other countries may not agree with that advice, especially if an alternative vaccine isn't available. Thomas Breuer, the chief medical officer of GSK Biologicals, said the pharmaceutical house "is committed to patient safety and to the highest manufacturing standards for all our vaccines and medicines," according to a company statement.
