The latest omicron boosters are 84% effective at keeping seniors 65 and older from being hospitalized with Covid-19 compared with the unvaccinated, according to a study published by the Centers for Disease Control and Prevention on Friday.
And seniors who received the omicron booster had 73% more protection against hospitalization than those who only received two or more doses of the original vaccines that were not updated to target omicron, according to the CDC.
The study was conducted from September through November when omicron BA.5 and the even more immune evasive BQ.1 and BQ.1.1 variants were dominant. About 800 seniors with a median age of 76 were included in the analysis.
In a larger study that looked at more than 15,000 adults ages 18 and older, the omicron booster was 57% effective at preventing hospitalization. Adults who received the booster had 38% additional protection compared with people who only received the original shots.
Neither study examined how well people were protected against hospitalization if they were vaccinated and had natural immunity from a previous Covid infection.
A previous study from the CDC found that the boosters were less than 50% effective at preventing mild illness across most age groups. But prominent scientists and public health experts said the shots’ effectiveness against hospitalization would almost certainly be higher.
U.S. health officials have repeatedly called on everyone who is eligible to get an omicron booster ahead of the holidays. But the administration has focused in particular on making sure more vulnerable populations, such as older adults, stay up to date on their Covid vaccines.
Dr. Ashish Jha, the White House Covid task force leader, has said most of the people dying from Covid right now are seniors who are not up to date on their shots or are not receiving treatment when they have breakthrough infections.
“There are still too many older Americans who have not gotten their immunity updated, who have not gotten themselves protected,” Jha told reporters at the White House on Thursday.
The Biden administration is launching a campaign to increase vaccinations in nursing homes, whose residents are some of the most vulnerable to severe Covid. Less than 50% of nursing home residents have received the updated booster.
Overall, only 35% of seniors have received an omicron booster, while 14% of people ages 5 and older have gotten the updated shot, according to CDC data.