COVID-19 booster vaccinations extend protection against moderate and severe cases for four to five months, according to a national study co-authored by researchers at Indianapolis-based Regenstrief Institute and other agencies across the country.
“While there have been recommendations for booster shots for a while, until now we haven’t had strong evidence of their effectiveness and how long that effectiveness lasts,” study co-author Brian Dixon of Regenstrief and Indiana University Richard M. Fairbanks School of Public Health said in written remarks.
“The recommendations to get boosted that were issued by the CDC months ago, were, in fact, the right recommendations,” Dixon added. “Booster doses are necessary to maintain a high level of immunity to severe COVID.”
The national study of 893,000 adults was designed to gauge the effectiveness and durability of the third and fourth doses of COVID vaccine boosters.
The study found that protection against hospitalization increased substantially after a booster shot but waned in four to five months. The waning pattern for the Moderna and Pfizer boosters were similar.
“If it has been four months or longer since your last COVID booster, or if you had the initial two shots and have never received a booster, you should strongly consider a bivalent booster, which targets ancestral strains of the COVID virus plus subvariants Omicron BA.4 and BA.5,” said study co-author Shaun Grannis, Regenstrief’s vice president for data and analytics.
The study’s authors estimate that booster shots could prevent 300 hospitalizations for severe COVID in the United States every week.
The study was conducted by the Centers for Disease Control and Prevention’s VISION Network. Aside from Regenstrief, other network members are Columbia University Irving Medical Center, HealthPartners, Intermountain Healthcare, Kaiser Permanente Northern California, Kaiser Permanente Northwest, University of Colorado and Paso Del Norte Health Information Exchange.