FDA says Pfizer COVID vaccine is highly effective, even after first dose

The coronavirus vaccine manufactured by Pfizer and BioNTech is highly effective and poses no significant safety risks, according to documents published by a Food and Drug Administration (FDA) advisory panel Tuesday.

The endorsement of the trial results means that FDA clearance for the two-dose vaccine could come shortly after the Vaccines and Related Biological Products Advisory Committee meets on Thursday to publicly review the evidence, and likely recommend authorization.

Agency staff conducted their own analysis of the research presented by the companies and found the vaccine was 95 percent effective at preventing COVID-19 infection a week after the second dose was administered.

The results also show some protection begins even after the first dose, but the report cautioned that two doses are still needed. COVID cases tapered off in the vaccinated group shortly after the first dose was administered; 50 cases of COVID-19, compared with 275 cases in the placebo group.

Biggest unknown: The report gives a deep dive into the evidence, but because the virus, and the vaccines, are so new, it’s unclear how long protection lasts. The report showed protection at least through the two month monitoring period required by the FDA, but it has not been possible to monitor for longer.