On Monday, the FDA announced it would recommend against the use of the vaccine Rotarix made by GlaxoSmithKline until it can confirm it is completely safe to use. According to the Los Angeles Times, the vaccine was found by researchers to contain a pig virus called porcine circovirus 1, or PCV1. The drug is used to inoculate infants against rotavirus, which causes severe diarrhea and dehydration and is thought to cause more than 500,000 deaths in infants worldwide each year.
While the FDA says it has no evidence at this time that Rotarix has posed any safety risks, the agency recommends that health care providers switch to other available vaccines such as RotaTeq, manufactured by Merck. Preliminary tests have found no traces of PCV1 in this vaccine.
The L.A. Times reports that until RotaTeq was introduced in the U.S. in 2006, rotavirus caused an estimated 50,000 hospitalizations and several dozen deaths each year. Rotarix was introduced in 2008. Most U.S. children who have been vaccinated against rotavirus have received RotaTeq, the FDA said. About 1 million have received Rotarix.
The FDA is researching how the virus may have been introduced into the vaccine and whether it contains intact portions of the PCV1 or only fragments of the virus. The Times reports that according to a statement by manufacturer GlaxoSmithKline, the World Health Organization and the European Medicines Agency are not expected to change their current guidelines for using the drug, as they feel the benefit from the vaccine still outweighs any potential risks.
On its website, the FDA assures parents and caregivers that the available evidence supports the safety of the vaccine as PCV1 is not known to cause disease in humans. The FDA’s recommendation to pull Rotarix to is a precaution taken while the agency studies the situation. Children who received Rotarix need no additional medical follow-up. The agency recommends that caregivers check with their child's doctor or nurse if they are concerned about which vaccine they received.