The mRNA Covid vaccines remained “highly effective” at preventing severe illness and death even as their protection against infection waned during the Omicron wave, The Washington Post reports.
Though the Pfizer and Moderna vaccines were not as effective at preventing infections during Omicron as they were during previous waves, both vaccines provided strong protection against hospitalizations and deaths, according to data from the Centers for Disease Control and Prevention.
The study also confirmed that booster shots helped expand protection against Omicron.
“Three doses was better than two — this report highlights the value of the third booster dose,” William Moss, executive director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health, said of the data.
The two-dose vaccine provided strong protection against needing to be put on a ventilator but a three-dose regimen was far more effective.
In all, the CDC found that the vaccine was 79% effective in preventing ventilation or death among people who got the first two doses.
The booster was 94% effective at preventing ventilation and death.
“Anybody who is skeptical really needs to look at that number and think, ‘Okay, maybe I’m going to get a cold and feel sick, but … I’m not going to get put on a ventilator or die,’” Jeanne Marrazzo, director of the Division of Infectious Diseases at the University of Alabama at Birmingham, told the Post.
Though the booster dose provided stronger protection, data suggests that the immunity wanes relatively quickly. Some medical experts have discussed a fourth vaccine dose to counter the waning protection.
Pfizer has already asked the Food and Drug Administration to approve a fourth dose of its vaccine for those over 65 while Moderna asked regulators to approve a fourth dose for all adults and determine which patients should get priority.
Experts say a fourth shot could help alleviate severe disease from subsequent variants as a new variant called BA.2 begins to gain traction in Europe and Asia.
“It wasn’t included in these studies, but nonetheless, every indication that we have is that the vaccines will continue to provide very, very good protection against serious disease, even against BA.2,” William Schaffner, an infectious-disease specialist at Vanderbilt University Medical Center, told the Post.