Pfizer and Johnson & Johnson (J&J) have asked the US Food and Drug Administration (FDA) to provide clarity over retaining and attracting participants for COVID-19 vaccine trials after a vaccine becomes available to the public.
The comments were made in letters sent before an FDA advisory committee met yesterday to discuss issues relating to the development and authorisation of potential COVID-19 vaccines.
J&J urged the FDA committee to discuss the potential challenges of continuing trial enrolment in large-scale studies after the vaccines receive approval.
There is concern that individuals could be wary of enrolling in trials if they know they may receive a placebo shot as opposed to the COVID-19 vaccine.
Prior to the meeting, Pfizer officially asked the FDA if it could offer its vaccine candidate to participants in the placebo arm if their vaccine received approval, according to Endpoints News.
The committee debated what should be required to authorise or approve a COVID-19 vaccine and discussed the actions that the FDA had so far taken in the months since the pandemic began.
Within the discussions, some outside experts had doubts over the FDA guidelines recommending that a vaccine must have at least two months of safety data before being submitted for an emergency use authorisation (EUA).
Earlier this week, Pfizer’s chief executive officer Albert Bourla said that the company could submit an EUA for its BioNTech-partnered vaccine in the third week of November.
The company is awaiting a key data readout later this month, with Bourla adding that the company may know whether or not the vaccine is effective by October.
However, this depends on the number of COVID-19 cases in the phase 2/3 trial, which must reach a certain number in order to compare the effectiveness of the vaccine compared to placebo.
J&J, on the other hand, paused its COVID-19 vaccine study last week after a participant in its phase 3 study developed an unexplained illness.
Aside from confirming the participant illness, the company offered no further details regarding the nature of the adverse event and added that the vaccine study is not currently under clinical hold.
“We must respect this participant’s privacy. We’re also learning more about this participant’s illness, and it’s important to have all the facts before we share additional information,” J&J added