Dec. 17, 2022 — The updated bivalent COVID-19 boosters are keeping people out of the hospital and emergency room, especially seniors, according to two studies released Friday by the U.S. Centers for Disease Control and Protection.
One studyshowed people who received the bivalent booster had a 57% reduced risk of hospitalization compared with unvaccinated people, a 38% reduced risk compared to people who’d recently been vaccinated with monovalent vaccines, and a 45% reduced risk compared to people whose last dose of monovalent vaccine was at least 11 months earlier.
A second study found that among people over 65, the bivalent booster cut the risk of hospitalization by 84% compared to unvaccinated people and by 73% compared to people who’d gotten at least two doses of the monovalent vaccine.
“These studies show pretty unequivocally that the vaccines provide about 40 to 80% extra protection. So put another way, that can cut an individual’s risk of hospitalization due to COVID-19 and about half,” said Ruth Link-Gelles, MD, program lead on a CDC task force examining vaccine effectiveness, according to ABC News.
The bivalent boosters were designed to offer double protection — against Omicron subvariants BA.5 and BA.4 as well as older strains such as Delta. Both studies were conducted from September to November when Omicron variants caused the most infections.
Researchers said more studies are needed to determine if the bivalent booster provides protection against newer Omicron subvariants BQ.1.1 and BQ.1, which now account for 38.4% and 30.7% of current cases, according to recent CDC data. BA.5 accounts for 10% of current cases.
Vaccine maker Pfizer says studies indicated that its bivalent booster appears to protect against newer subvariants.
Among people over 5 years old, 73% have completed a primary vaccination series but only 14.1% have gotten the bivalent booster, the CDC says. Among people over 65 years, 93.9% have completed a primary vaccination series but only 35.7% have gotten the updated booster.
