New Data: Boosters Work Against Omicron

Full vaccination provides the best—and safest—protection from the delta and omicron coronavirus variants, new studies released Friday by the CDC confirm. It's the first comprehensive examination of the vaccines' effectiveness in preventing hospitalization for omicron infections, the Wall Street Journal reports. Booster shots were shown to make a major difference. One study found that a month after the second shot, the Pfizer vaccine wasn't doing much on antibody immunity against omicron. A third dose, however, bumped protection up past 50%.

An analysis showed the Pfizer or Moderna boosters to be 90% effective at keeping patients out of the hospital and 82% effective in preventing emergency room or urgent care trips, per the Washington Post. The data was collected from last August until Jan. 5; for three weeks of that stretch, omicron was dominant. Boosters protect against serious illness much more than against mild infections. Health officials said they hope the data persuades more people to receive a third dose of vaccine. "We should be celebrating this,” said a molecular medicine professor. Health officials should spread the message that boosters "are holding up the wall against severe disease … and that’s phenomenal," Eric Topol said.

The third shots are attracting fewer people than the first two. The CDC reports 39% of vaccinated people have received a booster, though US health officials have promoted it and other studies, from the US and other countries, have shown it to be effective. The CDC recommends the booster for everyone 12 and older who's at least five months past their second Pfizer or Moderna shot. Two shots have become less effective since omicron arrived, said Mark Thompson, a CDC epidemiologist and lead author of one of the new reports. "We have lacked this level of data," said another expert who hopes the studies settle the debate on boosters. "There’s uncertainty as decisions are made, and these recent papers are filling in the blanks," said Joshua Sharfstein. (More COVID booster shots stories.)