Paediatricians in the US have been told to stop using a drug used to treat diarrhea in babies after finding it may be contaminated.
The US Food and Drug Administration found Rotarix, which is manufactured by GlaxoSmithKline, may have traces of a benign pig virus.
But Dr Margaret Hamburg, of the regulatory body, said the decision was a difficult one to make as the risk is minimal.
She said: “This was a difficult decision for us to make because there is no evidence at this time that there is a risk to patients who have received this vaccine, and we know there are real benefits for children to be vaccinated against rotavirus.”
Dr Hamburg added the FDA did not want to scare parents.
Regulators in Europe have not changed their advice on how Rotarix is used while tests continue to be carried out.
Rotarix, an oral vaccine, is made from a weakened strain of human rotavirus that has to be grown inside living cells before being purified into a vaccine dose. Glaxo uses a line of monkey kidney cells, or vero cells.
Dr Hamburg said the pig virus DNA fragments have been found in Glaxo’s cell bank, meaning they were present from the vaccine’s earliest development. How the original contamination occurred is under investigation.
Merck’s competing rotavirus vaccine RotaTeq is made by a very different process, and FDA’s testing showed no sign of the pig virus in it.
Copyright Press Association 2010