The coronavirus vaccine made by Pfizer and BioNTech provides strong protection against COVID-19 within about 10 days of the first dose, according to documents published by the Food and Drug Administration before a meeting of its vaccine advisory group. The documents were published ahead of Thursday’s meeting of outside experts to discuss whether the vaccine should be authorised for emergency approval in the US. It also came on the same day when Britain’s National Health Service started vaccinating its oldest citizens with the Pfizer-BioNTech shots, making it the first clinically authorised, fully tested immunisation effort in the world.
A panel of independent scientists will pick apart the FDA’s first-pass review before recommending whether the vaccine appears safe and effective enough for millions of Americans. The FDA, which typically follows the committee’s advice, is expected to issue a decision in the days following the review. If given the green light, the first recipients would be health care workers and nursing home residents according to plans laid out by each state. Pfizer and its German partner BioNTech previously reported the shots to appear 95 per cent effective at preventing mild to severe Covid-19 disease in a large, ongoing study.
The vaccine’s swift impact could benefit not just the people who get it but the country’s strained hospitals, curbing the flow of new patients into intensive care units. Despite the early protection afforded by the first dose, it’s unclear how long that protection would last on its own, underscoring the importance of the second dose. Previous studies have found that the second dose of the Pfizer-BioNTech vaccine gives the immune system a major, long-term boost, an effect seen in many other vaccines.
Even if the vaccine is authorized by the F.D.A., the trial will continue. In the briefing documents, the companies said that they would encourage people to stay in the trial as long as possible, not knowing whether they got the vaccine or the placebo, so that the researchers could continue to collect information about whether the vaccine was safe and effective.
