Clinical trials involving approximately 38,000 participants suggest that the Pfizer-BioNTech vaccine has a positive safety profile and poses no concerns that would prevent emergency use authorization, the US Food and Drug Administration (FDA) said on Tuesday.
“Safety data from approximately 38,000 participants ≥16 years of age randomized 1:1 to vaccine or placebo with a median of 2 months of follow up after the second dose suggest a favorable safety profile, with no specific safety concerns identified that would preclude issuance of an EUA,” the FDA said in a briefing document.
The briefing document, released ahead of a scheduled meeting on Thursday to discuss emergency use authorization (EUA) for the vaccine, concludes that the clinical study "met the prespecified success criteria," an indication that the FDA will likely grant approval for the drug.
The FDA document revealed, however, that two patients who received Pfizer-Biontech's coronavirus vaccine during the trials died after receiving the injections.
“A total of six (2 vaccine, 4 placebo) of 43,448 enrolled participants (0.01%) died during the reporting period from April 29, 2020 (first participant, first visit) to November 14, 2020 (cutoff date),” the FDA said in briefing documents released ahead of a scheduled Advisory Committee meeting on Thursday to discuss emergency use authorization for the vaccine.
Both of the vaccine recipients were over the age of 55 years old, the documents said. One patient experienced a cardiac arrest 60 days after receiving a second dose of the vaccine and died three days later. The other patient with baseline obseity and pre-existing atherosclerosis died from arteriosclerosis three days after receiving a first vaccination.
However, the FDA document largely praised the safety results of the trial and said vaccination could even benefit individuals previously infected with COVID-19.
“Only 3% of participants had evidence of prior infection at study enrollment, and additional analyses showed that very few COVID-19 cases occurred in these participants over the course of the entire study,” according to the documente.
Data, according to FDA, suggest that “previously infected individuals can be at risk of COVID-19 and could benefit from vaccination.”
Last week, the UK became the first country in the world to grant emergency use approval to the candidate vaccine produced by US pharmaceutical giant Pfizer and German firm BioNTech.
In mid-November, Pfizer announced that their candidate vaccine concluded phase 3 clinical trials, with a declared efficacy level of 95 percent.
