GlaxoSmithKline’s infant rotavirus vaccine, Rotarix, has been found to contain a pig virus, prompting the Food & Drug Administration (FDA) to advise doctors to stop using it temporarily.
The discovery of this virus, called porcine circovirus 1, or PCV1, was made by an independent U.S. academic research team, using a novel technique that revealed DNA from PCV1 in Rotarix. Follow-up tests by GlaxoSmithKline and FDA scientists confirmed the academic team’s findings and confirmed that viral components have been present since the early stages of the vaccine’s development, including during clinical studies.
The agency is now attempting to determine whether the vaccine contains intact PCV1 or simply viral fragments, as well as how it got into the vaccine. The FDA said it would convene an expert advisory panel in four to six weeks to make further recommendations on the use of rotavirus vaccines.
According to the FDA, PCV1 is not known to cause illness in humans, and no adverse effects have been observed in children vaccinated with Rotarix. However, as a precaution, the agency is recommending that clinicians temporarily suspend using Rotarix as the agency learns more.
Preliminary testing by both the academic researchers and FDA scientists of RotaTeq has not detected components of PCV1, the FDA said. For the time being, the agency is recommending that healthcare providers use RotaTeq.
According to the FDA, the vast majority of U.S. children receive the RotaTeq vaccine, but about 1 million have received Rotarix. Many pediatricians have switched to Rotarix because it only requires two doses, while RotaTeq requires three. Both vaccines are administered to infants by mouth.