The presence of components of PCV1 in Rotarix was discovered when an independent U.S. academic research team applied a new technology for detecting viral genetic material. The researchers detected DNA fragments of PCV1 in two lots of the Rotarix vaccine.
The researchers notified GlaxoSmithKline of their findings on February 9, 2010. The company then initiated extensive experiments to confirm the results and investigate further. These included a series of assessments on the same two lots of the finished vaccine, as well as on vaccine materials at different stages of the production process. These follow-up tests confirmed the presence of many copies of DNA from PCV1 in the two finished vaccine lots that had previously been tested, in intermediates in the production process, and in the working cell bank and viral “seed” from which the vaccine was derived.
The firm notified FDA of its findings on March 15, 2010. FDA staff then began to review the evidence, initiate its own testing, consult with experts, contact other public health officials in the U.S., and communicate with international partners.
Has DNA from PCV1 been found in other lots of Rotarix?
In its follow-up assessments, GlaxoSmithKline detected the presence of DNA from PCV1 in the working cell bank and viral “seed” used to produce Rotarix, confirming that the material has been present since the early stages of product development, including during clinical studies.
Why wasn’t the presence of DNA from PCV1 detected in previous reviews of Rotarix?
Circoviruses such as PCV1 have not been associated with illnesses in humans, and FDA has not required the routine testing of vaccines for these viruses. Current FDA guidance, released in March 2010, recommends that manufacturers consider testing for these agents. FDA introduced this recommendation as an additional precaution for vaccines manufactured with animal-based components. The agency is reviewing the current situation and may update its approach based on additional findings.
How did DNA from PCV1 come to be present in Rotarix?
At this time, FDA does not know how DNA from PCV1 came to be present in Rotarix. FDA and GlaxoSmithKline are investigating this question.
Does the detection of DNA from PCV1 indicate that the virus is present in Rotarix?
Although DNA fragments from PCV1 have been detected in Rotarix, it is not yet known whether this means that intact virus is present. Additional studies are currently being conducted to establish whether or not intact PCV1 is present in Rotarix.
Does the detection of DNA from PCV1 in Rotarix raise special concerns for influenza vaccines?
No. The manufacturing process for Rotarix is very different from the manufacturing process for influenza vaccines. Unlike Rotarix, a cell-based vaccine, the influenza vaccines currently on the market are egg-based vaccines. The cell-based influenza vaccine currently in development uses materials that are different from the one used to develop Rotarix.