NEW YORK (AP) — Older U.S. adults should roll up their sleeves for another COVID-19 shot, even if they got a booster last fall, an influential government advisory panel said Wednesday.

The panel voted 11-1 to say Americans 65 and older should get another dose of the updated vaccine that became available in September — if at least four months has passed since their last shot. The committee advises the head of the Centers for Disease Control and Prevention, who will decide whether to sign off on the recommendation.

The panel’s decision came after a lengthy discussion about whether to say older people “may” get the shots or if they “should” do so. That reflects a debate among experts about how necessary another booster is and whether yet another recommendation will add to the public’s growing vaccine fatigue.

Some doctors say most older adults are adequately protected by the fall shot, which built on immunity derived from earlier vaccinations and exposure to the virus itself. And preliminary studies so far have shown no substantial waning in vaccine effectiveness over six months.

However, the body’s vaccine-induced defenses tend to fade over time, and that happens faster in seniors than in other adults. The committee had recommended COVID-19 booster doses for older adults in 2022 and 2023.

COVID-19 remains a danger, especially to older people. There are still more than 20,000 hospitalizations and more than 2,000 deaths each week due to the coronavirus, according to the CDC. And people 65 and older have the highest hospitalization and death rates.

Some members of the advisory panel said a “should” recommendation is meant to more clearly prod doctors and pharmacists to offer the shots.

“Most people are coming in either wanting the vaccine or not,” said Dr. Jamie Loehr, a committee member and family doctor in Ithaca, New York. “I am trying to make it easier for providers to say, ‘Yes, we recommend this.’”

In September, the government recommended a new COVID-19 shot recipe built against a version of the coronavirus called XBB.1.5. That single-target vaccine replaced combination shots that had been targeting both the original coronavirus strain and a much earlier omicron version.

Agency officials say that among those who got the latest version of the COVID-19 vaccine, 50% fewer will get sick after they come into contact with the virus compared with those who didn’t get the fall shot.