Leading researchers and bioethicists have signed a letter urging Pfizer to delay submitting a marketing authorisation application for its potential COVID-19 vaccine, reported Bloomberg.
The letter comes after reports last week that Pfizer and its partner BioNTech were expecting conclusive results from a study of their mRNA-based shot in October, raising concerns that the companies could seek regulatory approval before achieving convincing safety data.
The researchers urged Pfizer and BioNTech to delay filing the vaccine candidate with the US Food and Drug Administration (FDA) until after the companies had access to follow-up safety data.
They added that Pfizer’s clinical trial needs to monitor participants for at least another two months after they have received a second dose of the vaccine candidate, BNT162b2.
‘To be successful, the public needs to have the utmost trust in the vaccine and the science behind it,’ the letter said.
‘Submission of an application for an Emergency Use Authorisation (EUA) before this standard is met would severely erode public trust and set back efforts to achieve widespread vaccination,’ the experts added.
In early study results, Pfizer’s vaccine candidate elicited promising antibody levels against the SARS-CoV-2 virus, which causes COVID-19. BNT162b encodes an optimised SARS-CoV-2 full length spike glycoprotein and is also mRNA-based.
An mRNA vaccine tricks the body into producing some of the targeted viral proteins that, in turn, can be detected by the immune system, which begins to produce antibodies against them.
This technology is so new that, currently, no mRNA-based vaccine has been approved for any infectious disease anywhere in the world.
Pfizer is among a number of top companies that signed a pledge earlier this month promising to uphold rigorous safety and efficacy protocols during and after the clinical development of their respective candidates.
The pledge was also co-signed by the CEOs of AstraZeneca, Johnson & Johnson, Merck, Moderna and Novavax, as well as Sanofi and GlaxoSmithKline.
In the pledge, the biopharma leaders promised to ‘only submit (a vaccine) for approval or emergency use authorisation after demonstrating safety and efficacy through a phase 3 clinical study that is designed and conducted to meet the requirements of expert regulatory authorities such as the FDA’.
The crucial need for ensuring the safety of any potential vaccine has been further highlighted after AstraZeneca was forced to put its clinical trial on hold after a participant developed a serious inflammatory condition.
Although the trial has been restarted in the UK, the US study is still on hold. According to the Financial Times, the University of Oxford told participants in a document that the adverse event was either unlikely to be associated with the vaccine or that there was ‘insufficient evidence’ that the two were or were not associated.