May 14, 2010 - Both rotavirus vaccines given to U.S. infants carry tiny amounts of pig virus or pig virus DNA -- but due to the vaccines' strong safety record, the FDA says doctors should resume their use.
Last March, the FDA suspended use of GlaxoSmithKline's Rotarix when newly available techniques detected DNA from porcine circovirus type 1 (PCV1) in the vaccine. Further research found whole PCV1 virus in the vaccine -- and showed that DNA from both PCV1 and the related PCV2 were in Merck's RotaTeq vaccine.
Neither PCV1 nor PCV2 causes disease in humans. Millions of doses of the vaccines have been given to infants with no sign of significant safety problems. Since rotavirus can cause life-threatening diarrhea, and since the risk from the pig viruses is only theoretical, the FDA is lifting its precautionary suspension of Rotarix and encouraging continued use of RotaTeq.
Meanwhile, the FDA is working with GlaxoSmithKline and Merck to plan follow-up studies. GlaxoSmithKline is redesigning its vaccine to eliminate the pig virus; Merck has not yet announced its plan.
Children who receive the vaccines do not need follow-up. Pig virus and pig virus DNA was in the vaccine when it was tested in tens of thousands of infants during clinical trials. No safety issues arose.