Pfizer’s Covid vaccine starts working almost 10 days after first dose, says US FDA
London, Dec. 9, 2020 (AltAfrica)–Pfizer-BioNTech’s Covid-19 vaccine begins working within almost 10 days of the first dose, according to new documents released by the US regulator ahead of an advisory meeting this week to discuss granting the vaccine an emergency approval
While FDA noted that protection begins to appear two weeks after the first dose, full protection wasn’t calculated until after the second dose. No one yet knows how long that protection lasts, something the still unfinished study eventually will need to answer
However, the US Food and Drug Administration, in its documents stated that Pfizer’s vaccine was strongly protective against COVID-19 and appeared safe — offering the world’s first detailed look at the evidence behind the shots.
The positive review from the US FDA sets the stage for a decision allowing the vaccine’s initial use within days. FDA regulators posted their analysis online even as across the Atlantic, Britain began vaccinating its oldest citizens with the shots, which were co-developed with BioNTech.
This is one of several vaccines in the pipeline being tested in the hope of ending the pandemic. The FDA later this month will consider a COVID-19 vaccine by Moderna and the National Institutes of Health.
Pfizer and its German partner BioNTech previously reported the shots appeared 95% effective at preventing mild to severe COVID-19 disease in a large, ongoing study. That’s based on the first 170 infections detected. Only eight of the infections were among volunteers given the real vaccine while the rest had received a dummy shot.
FDA’s reviewers agreed that the shots were strongly protective. And of special concern, they worked about as well in older adults, too, the agency confirmed. Among volunteers over age 55, there were three cases of COVID-19 infection who were vaccinated and 48 among placebo recipients. Five of the cases were among people 75 or older, and all had received the dummy shots.
In the two months that volunteers were tracked so far after the second dose, FDA’s reviewers said protection hadn’t begun waning.
The other critical issue: Safety. FDA reviewers said the vaccine has “a favourable safety profile, with no specific safety concerns” that would prevent a decision to allow emergency use.
The main side effects are injection-site pain or flu-like reactions that indicate the immune system is revving up. Those tend to last a day or two and are most common after the second dose: More than half of adults under 55 experienced fatigue or headache, about a third reported chills or muscle pain, and 16% had a fever. Older adults were less likely to experience those reactions, and the FDA said they were considered severe in less than 5% of participants.
The FDA found no serious side effects among the more than 37,000 volunteers who’ve been tracked for at least two months after their last dose, the time period when historically any vaccination problems appear. (Mint)