The new bivalent mRNA COVID-19 booster vaccines that began being used in September are beneficial in preventing COVID-19-associated hospitalization in persons 65 and over, according to a study released Friday by the Centers for Disease Control and Prevention (CDC) and the Investigating Respiratory Virus in the Acutely Ill (IVY) hospital network research group.
The multistate IVY hospital network collected data from 18 states from Sept. 8 through Nov. 30, 2022, showing that a bivalent booster dose provided 73% additional protection against COVID-19 hospitalization among immunocompetent adults ages 65 and over who had received past monovalent mRNA vaccination only.
“The results are strong and are showing benefit for bivalent COVID vaccine boosters this fall and winter,” said senior author and principal investigator Wesley Self, MD, MPH, Vice President for Clinical Research Networks & Strategy at Vanderbilt University Medical Center. “The booster shot targets the original COVID-19 strain in addition to the Omicron variant.
“These results support the recent recommendations that all eligible persons, especially adults ages 65 and over, receive a bivalent booster dose to maximize protection this winter,” he said.
Previous studies have shown that immunity from monovalent COVID-19 mRNA vaccines wanes over time. A bivalent, or “updated,” COVID-19 mRNA booster dose is currently recommended for all eligible persons, although little has been known about its effectiveness against COVID-19 hospitalization before this study.
The study released today shows 84% additional protection when compared with unvaccinated persons and 73% additional protection when compared with older adults who received two or more monovalent-only mRNA vaccine doses but not the bivalent booster dose.