Rotarix Had PCV1 DNA From Vaccine Inception
Recently detected DNA fragments of a common pig virus, circovirus type 1 (PCV1), in GSK’s Rotarix vaccine have been present since the early development of the vaccine, says the FDA. The agency reported that GSK found the PCV1 DNA fragments in the “working cell bank” and viral “seed” that was used to produce the oral vaccine. Consequently the contaminated Rotarix vaccine was assessed in clinical studies, which were the basis for FDA approval. The detection of PCV1 DNA fragments does not necessarily mean that intact virus was or is present in the vaccine; moreover, the virus itself is not known to cause human disease.
How GSK learned of the presence of PCV1 DNA fragments in Rotarix is somewhat sketchy in detail. According to the FDA, an “independent US academic research team,” while assessing a number of vaccines with a “new technology,” detected the PCV1 DNA fragments. After finding the DNA fragments in 2 lots of Rotarix vaccine, the researchers alerted GSK on February 9th. Follow-up tests by the company confirmed the presence of the DNA fragments in the 2 tested lots, as well as samples leading back to the seed virus. GSK notified the FDA on March 10th, and the agency, as a precautionary measure, suspended the use of Rotarix yesterday.
The GSK press release provides 2 references on PCV1:
Li L, Kapoor A, Slikas B, et al. Multiple diverse circoviruses infect farm animals and are commonly found in human and chimpanzee feces. J Virol. 2010;84:1674-1682. (From the Blood Systems Research Institute in San Francisco.)
Hatterman K, Roedner C, Schmitt C, Finsterbusch T, Steinfeldt T, Mankertz A. Infection studies on human cell lines with porcine circovirus type 1 and porcine circovirus type 2. Xenotransplantation. 2004;11:284;294. (From the Robert Koch Institut in Berlin.)
Li et al used something called viral metagenomics to identify “circovirus-like” DNA sequences in stool samples of humans and wild chimpanzees. Viral metagenomics is apparently a relative new field, in which researchers attempt to recover viral DNA from environmental samples (as opposed to laboratory cell lines).* In US adults, the detection of circovirus was limited to the discovery of porcine circovirus (which is also found in most US pork products, according to the authors).
Hatterman et al reported on their infection of human cell lines with PCV1, which did not cause “any visible changes,” unlike the type 2 PCV strain.
For children who require rotavirus vaccination, the FDA recommends the use of Merck’s Rotateq vaccine—which is evidently not contaminated with PCV1 DNA.
* The technique may (may) be the method by which PCV1 DNA fragments were detected in GSK’s Rotarix vaccine.
Image of Rotarix administration from Rotarix Prescribing Information.
03/26/10 addendum: Relying on reason and common sense, the European Medicines Agency reported today that it “sees no safety concerns with the Rotarix oral vaccine” and that the DNA of a virus that does not cause human disease “does not present a risk to public health.” The EMA stressed that PCV1 is commonly found in meat and other food products.
The agency, however, requested that 1) GSK identify how the DNA fragments got into Rotarix and 2) produce a vaccine that is free of PCV1 DNA. The agency also reported that other GSK vaccines do not contain PCV1 DNA.