The BMJ has reviewed the documents, which show that regulators had major concerns over unexpectedly low quantities of intact mRNA in batches of the vaccine developed for commercial production.
EMA scientists tasked with ensuring manufacturing quality—the chemistry, manufacturing, and control aspects of Pfizer’s submission to the EMA—worried about “truncated and modified mRNA species present in the finished product.” Among the many files leaked to The BMJ, an email dated 23 November by a high ranking EMA official outlined a raft of issues. In short, commercial manufacturing was not producing vaccines to the specifications expected, and regulators were unsure of the implications. EMA responded by filing two “major objections” with Pfizer, along with a host of other questions it wanted addressed.
Leaked documents show that some early commercial batches of Pfizer-BioNTech’s covid-19 vaccine had lower than expected levels of intact mRNA, prompting wider questions about how to assess this novel vaccine platform, writes Serena Tinari