Booster doses of the Pfizer-BioNTech and Moderna COVID-19 vaccines are 90 percent effective against hospitalization with the Omicron variant, The New York Times reports, per new data published by the Centers for Disease Control and Prevention on Friday.
Booster shots were also found to have "reduced the likelihood of a visit to an emergency department or urgent care clinic," and were shown most effective against infection and death in Americans aged 50 and older, the data revealed, per the Times.
The findings, spread across three new, large studies, are the "first real-life data to examine the effect of boosters against Omicron, which now accounts for more than 99 percent of coronavirus cases in the United States," reports CNN.
"Data from other countries have also shown significant benefit of getting the booster, but this is really showing it in the U.S.," said immunologist Akiko Iwasaki on Friday, per the Times. "These numbers should be very convincing."
Overall, however, the new data prove boosters more effective against the Delta variant than Omicron, which studies have shown able to circumvent the body's immune response, notes the Times.
For some, the question now becomes how we should define being "fully vaccinated."
"I think we have to redefine fully vaccinated as three doses," Dr. William Schaffner, a CDC vaccine adviser who was not involved in the studies, told CNN. "I think it's the third dose that really gives you the solid, the very best protection," he added.
Despite the overwhelmingly positive evidence in favor of boosters, "less than half of those eligible to receive booster shots have gotten one, and only about a quarter of the total US population is fully vaccinated and boosted," per CNN.