Pfizer Vaccine Inches to Approval; Extra Questions Raised over AZ’s Shot
The Pfizer / BioNTech vaccine against Covid-19 took another big step forward after the FDA released the results of its safety report. This document contains the information needed by the FDA’s Vaccines and Related Biological Products Advisory Panel, which is due to meet this week to decide whether to grant emergency approval for the vaccine.
The vaccine, a joint venture between US pharmaceutical company Pfizer and German BioNTech, is one of the first to be made available to the public. Pfizer revealed in a press release that the vaccine has been shown to be more than 90% effective against Covid-19 and has no serious safety concerns. Patients need two doses three weeks apart to achieve 90% effectiveness. The vaccine must be stored in extremely cold temperatures (the recommended storage environment is -70 ° C), which poses challenges for its widespread use.
The security clearance
The FDA’s Briefing Document provides a review of the information Pfizer provided to the agency. The data comes from a phase 3 clinical study with 44,000 participants. Pfizer’s safety data covered 38,000 of these participants, evenly split between placebo and vaccine groups. The information was recorded through November 14, 2020 and included two months of follow-up data.
The vaccine starts working one week after the first dose. In the study, 162 people in the placebo group became infected with Covid-19 and 8 received the actual vaccine. It appears to be similarly effective regardless of age, gender, ethnicity, and the presence of comorbidities. The briefing also suggests that the vaccine could help prevent recurring infections.
It is true that “no specific safety concerns were identified that would impede the issuance of a
EEA “does not mean that the vaccine is without side effects. After the briefing:
“The most common side effects were reactions at the injection site (84.1%), fatigue (62.9%), headache (55.1%), muscle pain (38.3%), chills (31.9%), joint pain ( 23.6%), fever (14.2%); Serious side effects occurred in 0.0% to 4.6% of participants, were more common after dose 2 than after dose 1, and were in participants aged 55 and over (≤ 2.8%) compared with younger participants (≤ 4.6 %) generally less frequently). The frequency of serious adverse events was low (
the next steps
An FDA panel is expected to make its decision on approval during a meeting on Thursday. This will not mark the end of safety testing as long-term follow-ups of ongoing clinical trials as well as new studies on health care workers, pregnant women, military families and veterans are planned. The panel will also consider what additional research will be required in the future.
Pfizer’s vaccine isn’t the only one in development. A similarly effective vaccine from competitor Moderna is also about to be approved. A third vaccine candidate from Oxford University and pharmaceutical company AstraZeneca is facing increased regulatory scrutiny and concerns from the scientific community about dosing issues and the trial’s failure to test a specific dose that was highly effective in people over 55. The New York Times reported yesterday, December 8th, that some participants had not received the required second dose for 3 months. According to the study protocol, it should have been given a month after the first shot.
The UK has already approved the Pfizer vaccine and recently started giving it to the elderly and vulnerable. The FDA panel review of the Moderna vaccine is scheduled for December 17th. The AstraZeneca vaccine is not yet ready for review.
Take them home
While the vaccine has not yet been approved for emergency use, passing this review is a huge step towards this milestone. Should the EUA be granted, vaccination could start soon, similar to the UK.
Sean Marsala is a Philadelphia, Pennsylvania-based health journalist. He loves technology, usually reads, surfs the internet, and explores virtual worlds.