Officials from the Food and Drug Administration are advising that doctors should temporarily stop using the vaccine against a diarrhea-causing virus because the vaccine is contaminated with an apparently harmless pig virus.
GlaxoSmithKline’s Rotarix is intended to prevent severe cases of rotavirus infections, a diarrheal illness that can cause dehydration in infants and young children.
Food and Drug Administration Commissioner Margaret Hamburg said March 22 that the virus is probably harmless and that the vaccine appears to be safe. The recommendation will stand until the agency discovers how porcine circovirus 1 (PCV-1) got into the vaccine and assesses its effects.
“We will keep the public and the clinical community updated on our findings,” Hamburg said.
The European Medicines Agency has asked the British manufacturer to look into how the DNA of a foreign viral strain got into Rotarix.
Switzerland has urged doctors to temporarily stop using the vaccine, regulators said March 23, making it the latest country to caution against its use.
PCV-1 is not known to cause illness in humans, GSK said, adding it is found in everyday meat products and is frequently eaten without causing disease or illness.
The World Health Organization said rotavirus kills 500,000 children a year globally.
“In many countries, rotavirus causes so much severe illness and death that the known benefits of continued use of Rotarix far outweigh any theoretical risk of harm from the vaccine,” said Dr. Thomas Frieden, director of the Centers for Disease Control and Prevention. “We anticipate that many countries will decide to continue vaccinating with Rotarix while more information becomes known.”
A second vaccine, made by Merck, remains available. RotaTeq was approved for use in the United States in 2006 and is still the more popular vaccine. Rotarix was approved in 2008 and has been used to vaccinate about 1 million children.
FDA said it will continue to gather more information about the PCV-1 components in Rotarix, including whether intact virus, as opposed to DNA fragments, is present. The agency is assessing current vaccine testing methods. In four to six weeks, FDA will convene an expert advisory committee and make additional recommendations on the use of rotavirus vaccines.
Thomas Breuer, CEO of GlaxoSmithKline Biologicals, said the company would continue producing the vaccine with the extraneous virus, which originated in pigs, until it could figure out a way to fix the process.
FDA will provide updates to patients, providers, and the general public as more information becomes available. The agency will also continue to communicate with the World Health Organization and counterpart regulatory agencies in other countries.