And if they do, will the US have the supplies for a mass rollout? After the European Union sped past the FDA in reauthorizing Johnson & Johnson’s vaccine using US data, the Washington Post reports that regulators here might just follow the EU’s example, perhaps as early as tomorrow. That relaunch might be easier proposed than accomplished, though:

Federal health authorities are leaning toward recommending that use of the Johnson & Johnson coronavirus vaccine resume, possibly as soon as this weekend — a move that would include a new warning about a rare complication involving blood clots but probably not call for age restrictions.

The position would be similar to one taken by Europe’s drug regulator, the European Medicines Agency, which said this week the Johnson & Johnson vaccine should carry a warning but placed no restrictions on its use. The European agency said the shot’s benefits continue to outweigh the risks.

The current stance of U.S. authorities was described by two government officials who spoke on the condition of anonymity to discuss internal deliberations. They said the position could be affected if there were a sudden flood of reports of blood-clot cases, which appears unlikely, or if other surprises emerged connected to the vaccine.

The EU had a rare moment of speedy clarity yesterday in returning J&J to the inoculation battle. The EMA determined that one case of blood clots in a million inoculations is less risky than the disease it prevents, especially as COVID-19 blood-clot complications occur at a far higher rate. Why the CDC and FDA didn’t come to the same conclusion in the past two weeks looks more like a bureaucratic obstacle rather than scientific caution:

That independent expert panel, the Advisory Committee on Immunization Practices, last met April 14. It reviewed the decision made the day before by the CDC and the Food and Drug Administration to recommend a temporary halt of the vaccine in response to reports of six cases of a severe type of brain blood clot among the more than 7.5 million people who had been inoculated at that time. The panel said at that meeting it needed more data before recommending an end to the pause or other steps, such as restrictions based on age or gender.

Couldn’t anyone call the group together for an ad hoc review of the data in between? With the inoculations paused, they had about all of the data they were going to get, especially since it only involved six cases, only one of which was fatal. The impact of halting the J&J vaccine over those six cases might be millions of more people getting less enthusiastic about the vaccines in general — since the FDA and CDC authorized J&J using the same emergency-use authorization process they used with Pfizer and Moderna.

This is still correlative rather than causative, but the CDC’s data on vaccination uptake shows a rather dramatic change since the J&J suspension — and it can’t be due to just the absence of that specific vaccine:

That’s the most dramatic fall-off in momentum since the Midwest winter storm derailed vaccination efforts across several states. In this case, the disaster looks man-made. Even with J&J back on the market, it might be difficult to recapture that momentum, thanks to the knee-jerk reaction and delayed counter-action at the CDC and FDA.

Not that J&J and its partner Emergent are helping matters. The number of doses available once the CDC and FDA get out of the way might be another issue, too:

Federal regulators have found serious flaws at the Baltimore plant that had to throw out up to 15 million possibly contaminated doses of Johnson & Johnson’s coronavirus vaccine — casting doubt on further production in the United States of a vaccine that the government once viewed as essential in fighting the pandemic.

The regulators for the Food and Drug Administration said that the company manufacturing the vaccine, Emergent BioSolutions, may have contaminated additional doses at the plant. They said the company failed to fully investigate the contamination, while also finding fault with the plant’s disinfection practices, size and design, handling of raw materials and training of workers.

“There is no assurance that other batches have not been subject to cross-contamination,” the F.D.A.’s 12-page report states.

The report amounted to a harsh rebuke of Emergent, which had long played down setbacks at the factory, and added to problems for Johnson & Johnson, whose vaccine had been seen as a game changer because it requires only one shot, can be produced in mass volume and is easily stored.

That one’s not on the FDA, even if they’ve screwed up vaccine enthusiasm with their other intervention. For now, the US will have to rely on J&J’s Netherlands production rather than domestic production, which means its impact will unfortunately be limited even when reauthorized.