A nurse administers a shot at the FEMA-supported COVID-19 vaccination site at Valencia State College on the first day the site resumed offering the Johnson & Johnson vaccine.  https://thebusinesstimes.co.uk

Paul Hennessy | LightRocket | Getty Images

An influential Food and Drug Administration advisory committee on Friday said the agency should authorize boosters of Johnson & Johnson‘s single-shot Covid-19 vaccine to the more than 15 million Americans who have already received the initial dose.

The unanimous vote – by the agency’s Vaccines and Related Biological Products Advisory Committee – is a critical step before the U.S. can begin giving second shots to J&J recipients, some of whom have said they are anxious to get the additional protection. One dose of J&J’s vaccine has been shown in studies to be comparatively less effective than the two-dose messenger RNA vaccines made by Pfizer–BioNTech and Moderna. The panel recommended the doses to everyone 18 and over who’s already received J&J’s first shot with many committee members saying it should be considered a two-dose vaccine much like Moderna and Pfizer’s.

The same committee on Thursday recommended Moderna booster shots to people ages 65 and older and other high-risk adults, in line with guidelines for Pfizer’s vaccine.

The FDA usually follows the advice of the committee, and a final decision by its regulators could come within days. The agency is not the final go-ahead, however. Next week, a Centers for Disease Control and Prevention vaccine advisory group will decide who should get the extra J&J shots. If it issues a recommendation and CDC Director Dr. Rochelle Walensky signs off, booster shots could begin immediately.