The updated COVID-19 booster shots provide additional protection against infection compared to previous shots, according to a new study from the Centers for Disease Control and Prevention.
Updated boosters from Pfizer-BioNTech and Moderna that targets both the original strain of the virus from 2020 and the omicron subvariants BA.4 and BA.5 offered additional protection against symptomatic COVID-19 infections when those who received the omicron boosters were compared to people who had received two, three or four doses of the original vaccines.
“It is clear now, despite the initial bit of confusion, that the BA.4-5 bivalent booster, what we refer to as the updated vaccine, clearly induces a better response against BA.4-5 and sublineages of BA.4-5 than does the ancestral strain,” said Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases and chief medical adviser to President Joe Biden, at the White House briefing Tuesday.
The CDC study is the first to look at how the boosters perform in the public. It found that when the updated booster was administered eight months or more after a person’s last COVID-19 shot, the vaccine was 56% effective at preventing symptomatic disease in people ages 18-49, 48% among those ages 50-64, and 43% among those age 65 and older.
The updated booster was less effective at preventing symptomatic illness in those who received it within two to three months of getting their last shot, with it being 30% effective among people ages 18-49, 31% among those ages 50-64, and 23% in those age 65 and older. The results indicate that people could still get breakthrough COVID-19 infections despite receiving the updated booster.
The study analyzed more than 360,000 viral tests among adults who received COVID-19 testing at nearly 10,000 retail pharmacies between Sept. 14 through Nov. 11, 2022, that had one or more symptoms associated with COVID-19.
The results come as an uptick for the updated booster vaccines remains lackluster since they were first authorized in September. Roughly 35 million, or approximately 11%, of people ages 5 and older in the United States have gotten updated boosters so far, according to the CDC. The federal government purchased over 170 million doses of the updated shots from Pfizer-BioNTech and Moderna before the boosters were authorized.
The Biden administration has been hoping to get booster numbers up for the holiday season. On Tuesday, the administration started a six-week campaign focused on getting seniors and communities hit hard by COVID-19 their booster shots by allocating additional funding for community health centers and community-based organizations.