FDA lifts pause of J&J vaccine amid blood clot study.

U.S. health officials lifted an 11day pause on using Johnson & Johnson’s single-dose COVID-19 shot Friday after scientific advisers decided its benefits outweighed the risk of a rare blood clot.

The government said 15 vaccine recipients — out of nearly 8 million people given the J&J shot — developed an unusual kind of clot. All were women, most under age 50. Three died and seven remain hospitalized.

But ultimately, federal health officials decided J&J’s one-and-done vaccine is critical to fight the pandemic and that the small clot risk could be handled with warnings to help younger women decide if they should use that shot or an alternative.

“This is not a decision the agencies reached lightly,” Janet Woodcock, acting commissioner of the Food and Drug Administration said late Friday.

The Centers for Disease Control and Prevention said the J&J vaccine has important advantages for some people who were anxiously awaiting its return. And the FDA updated online vaccine information leaflets for would-be recipients and health workers so that shots could resume as early as Saturday.

While J&J shot is not widely administered at Houston-area vaccine sites, the places that do use it say they’re ready to switch back to the one-dose shot. Many likely will resume sign-ups next week.

“We anticipate putting J&J back into our strategy within a week of the updated CDC/FDA guidance,” Houston Health Department spokesman Scott Packard said.

The department has 300 J&J vaccines in stock, and it said it doesn’t expect any significant effect on its operations.

Harris County Public Health planned to substitute Pfizer vaccines in place of the J&J shots, but the department said it’s ready to return to J&J when it gets the goahead. Harris County had 60,000 J&J vaccines available when they were put on pause.

The U.S. government decision comes after advisers to the CDC debated the risk in a daylong meeting. Panelists voted 10-4 to resume vaccinations without age restrictions but made clear that the shots must come with clear warnings about the clots.

“I think we have a responsibility to be certain that they know this,“said Dr. Sarah Long of Drexel University College of Medicine, who voted against the proposal because she felt it didn’t go far enough in warning younger women.

The committee members all agreed the J&J vaccine “should be put back into circulation,” panel chairman Dr. Jose Romero, Arkansas’ health secretary, said after the vote. “The difference was how you convey the risk. … It does not absolve us from making sure that people who receive this vaccine, if they are in the risk group, that we inform them of that.”

CDC Director Dr. Rochelle Walensky said she hoped the pause would increase confidence in vaccine safety, showing “that we are taking every one of those needles in a haystack that we find seriously.”

Earlier this week, European regulators likewise decided the clot risk was small enough to allow the rollout of J&J’s shot there. But how Americans ultimately handle J&J’s vaccine will influence other countries that don’t have as much access to other vaccination options.

Dr. Paul Stoffels, J&J’s chief scientific officer, pledged that the company would work with U.S. and global authorities “to ensure this very rare event can be identified early and treated effectively.”

At issue is a weird kind of blood clot that forms in unusual places, such as veins that drain blood from the brain, and in patients with abnormally low levels of the platelets that form clots. Symptoms of the unusual clots, dubbed “thrombosis with thrombocytopenia syndrome,” include severe headaches a week or two after the J&J vaccination, rather than right away, as well as abdominal pain and nausea.

The government initially spotted six cases of the rare clots, with nine more cases coming to light in the past week or so. But even the first handful of reports raised alarm because European regulators already had uncovered similar rare clots among recipients of the AstraZeneca vaccine. The AstraZeneca and J&J shots, while not identical, are made with the same technology.

European scientists found clues that an abnormal platelet-harming immune response to AstraZeneca’s vaccine might be to blame — and if so, doctors should avoid the most common clot treatment, a blood thinner called heparin.