The Centers for Disease Control and Prevention released new data late Thursday on the risks of hospitalization and death from COVID-19 in unvaccinated and vaccinated people, with and without booster doses.
The numbers confirm that booster doses are most beneficial for older adults, as the CDC has previously reported. But the new numbers for young Americans were less compelling. In these age groups, the vaccination itself reduced the risk of hospitalization and death so greatly that a booster shot did not seem to provide much benefit.
The data only runs through the end of December, when the omicron’s surge had just begun.
Yet several recent studies have shown that vaccination alone, without a booster, remains strongly protective against serious illness and death in most people, even after the onset of omicron.
“I don’t think these data support a universal booster rollout for everyone,” said Dr. Celine Gounder, infectious disease expert and public health researcher at Kaiser Health News.
Boosters seem most essential for the elderly, she said, and those with certain immune conditions or living in long-term care facilities.
As of December 25, the hospitalization rate among unvaccinated adults over the age of 65 was 246 per 100,000 people. This rate fell to 27.4 per 100,000 in those vaccinated without a booster and to 4.9 in those who were vaccinated and received a booster.
There were about 44 deaths per 100,000 unvaccinated adults aged 65 and over. Vaccinations have brought that number down to around 3.6 deaths per 100,000, or one-twelfth more. Booster shots reduced the rate further, to around 0.5 deaths per 100,000, a figure 90 times lower.
But such risk comparisons were less useful in younger people, for whom the rate of serious consequences was already low.
Among adults ages 50 to 64, 73 per 100,000 unvaccinated adults were hospitalized, compared to 9 per 100,000 among those who were vaccinated and 2 per 100,000 among those who also received a booster shot.
Recalls made less of a difference to the number of COVID-19 deaths in this age group. Vaccinations reduced the rate to 0.4 deaths per 100,000, down from 8.26 per 100,000. With boosters, that number fell to 0.1 deaths per 100,000 people.
The agency did not provide hospitalization figures for adults 18 to 49, possibly because the numbers were too small.
This article originally appeared in The New York Times.