Unvaccinated adults age 65 or older who contracted the coronavirus were 49 times more likely to require hospitalization than seniors who had received booster vaccine doses, according to new data from the Centers for Disease Control and Prevention.

Marvin Marcus, 79, receives a COVID-19 booster shot in September 2021. Associated Press

Unimmunized adults in that age group were also 17 times more likely to be admitted to a hospital than those who had received either two shots of an mRNA vaccine or one Johnson & Johnson dose. Meanwhile, unvaccinated people between 50 and 64 years old were 44 times more likely to need hospitalization compared with their boosted counterparts.

The CDC figures on boosters, drawn from between October and December 2021, provide a real-world snapshot of the efficacy of commonly used vaccines in the United States. The European drug regulator also said Friday it was becoming “increasingly clear that a booster dose is needed to extend vaccine protection,” particularly against the omicron variant.