A Pfizer Inc. and BioNTech SE vaccine candidate was more than 90% effective in protecting people against the coronavirus, according to an early analysis of clinical trial results per Reuters.
The drugmakers, reporting no serious safety concerns, expect to seek US emergency use authorization later this month.
The results are likely to stir “cautious excitement—and relief,” STAT reports. Researchers thought a vaccine might only be 60-70% effective. But there were +90% fewer symptomatic COVID-19 cases among trial participants receiving 2 injections compared with those receiving a placebo.
Independent scientists warned against hyping the results without long-term data, The New York Times reports.
Among the remaining unknowns:
- Whether the vaccine prevents severe cases
- The duration of protection
- Whether it prevents people from carrying SARS-CoV-2 without symptoms
But “if the results hold up,” they'd be “on par with highly effective childhood vaccines for diseases such as measles.”