PCV1, PCV2 DNA detected in RotaTeq

Evidence of contamination with porcine circovirus type 1 and type 2 has been found in RotaTeq, Merck’s pentavalent rotavirus vaccine, according to an FDA official who spoke during a hearing on rotavirus vaccines.

After discovering “very low levels” of porcine circovirus type 1 and type 2 (PCV1 and PCV2) DNA in RotaTeq, Merck researchers revealed their findings to the FDA. Officials said, however, these results do not indicate an immediate health threat.

“There is no evidence at this time that DNA from PCV causes any disease in humans,” Merck said on its website. “We remain confident in the safety profile and quality of RotaTeq.”

The FDA suspended use of the monovalent rotavirus vaccine Rotarix from GlaxoSmithKline in March after detecting PCV1, although officials said the virus did not appear to be harmful to humans. Despite the evidence of similar contamination in RotaTeq, however, the FDA has not recommended against using the vaccine.

“There is no evidence that PCV1 poses a safety risk,” said Norman Baylor, PhD, of the FDA’s Center for Biologics Evaluation and Research, at the Vaccines and Related Biological Products Advisory Committee meeting on Friday.

Research on PCV2 is lacking, however, and the FDA did not have information about the presence of PCV2 DNA in RotaTeq until shortly before Friday’s meeting.

Although GlaxoSmithKline’s researchers said their data show that the virus is not dangerous to humans, the company remains committed to eliminating PCV1 contamination from Rotarix by altering its manufacturing process.

“This is a complex process and will take time,” said Barbara Howe, MD, vice president of North American vaccine development for GlaxoSmithKline. Howe said GlaxoSmithKline plans to make Rotarix available again in the United States.

Merck has distributed 30 million doses of RotaTeq in the United States and 7 million doses worldwide. Rotarix has supplied 2.5 million doses in the United States, but David Martin, MD, MPH, acting chief of the FDA’s Center for Biologics Evaluation and Research, said GlaxoSmithKline has provided twice as many doses of Rotarix when compared with RotaTeq in foreign countries.

The Vaccine and Related Biological Products Advisory Committee meeting reviewed the data on Rotarix contamination and discussed the use of advanced analytical detection methods that are not currently applied to evaluating materials that are used in the production of vaccines. These sensitive tests were integral to discovering PCV1 in both rotavirus vaccines, panel members said.