Pfizer's COVID-19 booster provided significant protection against the omicron variant during a laboratory study, the drugmaker said Dec. 8.
On average, blood samples from people who received only two doses of Pfizer's vaccine saw a 25-fold drop in antibodies against the omicron variant. Blood samples from people who received three doses saw similar neutralization against the omicron variant as the two-dose series provided against the original coronavirus strain.
The researchers collected the blood samples three weeks after the second dose or one month after the booster.
"Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain, it's clear from these preliminary data that protection is improved with a third dose of our vaccine," Pfizer CEO Albert Bourla, PhD, said in a news release. "Ensuring as many people as possible are fully vaccinated with the first two dose series and a booster remains the best course of action to prevent the spread of COVID-19."
On Nov. 19, the FDA granted emergency use authorization to Pfizer and Moderna boosters for all adults.