Pig Virus DNA Found in Rotavirus Vaccine
FDA: No Problems Seen in 1 Million U.S. Kids Who Got Rotarix Vaccine
WebMD News Archive
March 22, 2010 -- GlaxoSmithKline's Rotarix rotavirus vaccine contains DNA from an
apparently harmless pig virus, the company and the FDA today announced.
The FDA estimates that 1 million U.S. kids have received the Rotarix
The contamination was discovered by researchers developing a new technique
for detecting viral material. GlaxoSmithKline confirmed that the pig virus,
porcine circovirus type 1 or PCV-1, has been in the vaccine since it was
This means that pig virus DNA was in the vaccine throughout clinical trials.
No safety issues emerged from these international studies with 90,000
participants or, GlaxoSmithKline says, in post-marketing surveillance covering
more than 69 million doses of the vaccine.
Nevertheless, as a precaution the FDA is asking doctors to stop using the
two-dose Rotarix vaccine, which it approved in 2008.
"The message is clearly not a message of safety but of caution going
forward," FDA Commissioner Margaret Hamburg, MD, said at a news conference. "We
believe the vaccine is both safe and effective and we strongly encourage
vaccination against rotavirus. But we want to more deeply understand the
finding of this unexpected material in the product, and that is why we are
putting a clinical pause on its use."
Alternative Rotavirus Vaccine Available
About 75% of U.S. doctors prescribe the three-dose RotaTeq vaccine, made by Merck, which was approved in
Because rotavirus causes severe diarrheal disease in infants, rotavirus
vaccination begins at age 2 months. The FDA says children who already received
one dose of the Rotarix vaccine should follow up with two doses of the RotaTeq
vaccine. Those who already received two doses of Rotarix should be fully
Merck's RotaTeq vaccine is made using a different process and is not
contaminated with PCV-1.
It's not at all clear what it means to have found PCV-1 DNA in a vaccine.
It's not yet clear whether the vaccine contains only fragments of the pig virus
or whether the vaccine contains whole virus capable of replication.
PCV-1 does not cause disease in humans. It does not even appear to cause
disease in pigs. According to GlaxoSmithKline, it's a common virus that's often
eaten in meat products with no resulting illness.