The move is intended to give the CDC and FDA time to answer questions about the clotting cases. At a news conference today, CDC and FDA leaders said they expected a review of data on the cases to take a matter of days. Most likely, J&J vaccinations will then resume with updated information about risk factors. (If you’re worried about yourself or loved ones, here’s what we know about risks so far).

But pausing vaccinations also raises questions about how to balance side-effect risks with the urgency of the vaccine rollout. The pause could slow the U.S vaccine campaign, which in theory could itself cost as many lives as a slim risk of clotting.

On deeper examination, the decision appears more clear-cut than the headline numbers suggest. First, the risk to vaccine recipients could be higher than it appears: while the J&J vaccine has been linked to dangerous clotting in only six cases, some researchers believe there is a common thread between the clotting seen in J&J patients and in those who have received the AstraZeneca vaccine (see below). Further, the incidents appear concentrated in a single group: adult women under 50 made up all six clotting cases so far. That means there’s more reason to examine the problem than a mere six cases out of 6.8 million doses would suggest.

Meanwhile, the risk to America’s vaccine campaign seems modest, at least in practical terms. The J&J shot still makes up just a small portion of America’s vaccine supply – less than 5% – and a recent manufacturing accident means J&J doses were already arriving slower than first expected. (The pause quickly extended to Europe and South Africa, where the immediate negative impacts could be much more significant.)

The big unknown, though, is how the American public – particularly its most disgruntled fringe elements – will interpret the pause. On the merits, a cautious pause seems like a clear example of the health system working as intended to ensure drug safety, especially since the J&J vaccine is being distributed under an emergency authorization and hasn’t undergone long-term trials.

But for the tiny cadre of disinformation entrepreneurs who are the source for most anti-vaccine messaging, the pause will certainly become ammunition – evidence that not just this vaccine, but all of them, are flawed. Today even saw a strange second-order phenomenon, as media critics and baseball pundits criticized the pause not on health and safety grounds, but out of fear that it would trigger other people’s vaccine skepticism.

There are few easy answers here, and it will take sociologists and health communications experts years to really figure out what impact the decision has on vaccine confidence.

But one thing is pretty obvious: these decisions would be a lot easier if Americans had a better grasp of science – and if the medical community would come up with an easier way to explain the true implications of complex, and often jargon-filled, clinical studies and ensuing real-world outcomes to the public.

David Z. Morris
david.morris@fortune.com
@davidzmorris

DIGITAL HEALTH

Abortion pills by mail. The Biden administration today said the FDA would allow courses of mifepristone and misoprostol, which together induce abortion, to be delivered entirely via telemedicine consultation for the duration of the coronavirus pandemic. The medicine has been approved since 2000 for inducing early-stage abortions (before 10 weeks) and is now the most-used method. Until now, the FDA has required that the first part of the two-part medication be dispensed in person, despite strong data showing that telemedicine is a safe and effective way to distribute it. The move is particularly significant because abortion facilities, already rare prior to the pandemic, have been closing at a faster pace, limiting many American womens' access. (New York Times)

INDICATIONS

Why adenovirus-based vaccines might encourage bloodclots. There are no answers at this point about what might be causing the very rare cases of low-platelet blood clotting seen in recipients of the AstraZeneca and, possibly, J&J vaccines. But Paul Offit of the Children’s Hospital of Philadelphia, who reviews vaccine data on an FDA panel, tells STAT news that he believes it is likely to be an issue common to all adenovirus-based vaccines. The specific mechanism of the clots may involve immune response to the protein platelet factor 4: Clots were seen in patients with elevated antibodies to the substance, suggesting similarities to rare responses to heparin treatment. (STAT news)

THE BIG PICTURE

African health workers aren’t getting vaccinated fast enough. Sub-Saharan nations including Kenya and South Africa are still struggling to vaccinate health care workers. That’s a product both of rich nations buying up early batches of vaccine and, more recently, export restrictions by India. One serious wrinkle here is specific to sub-Saharan Africa. There is evidence that COVID-19 caused fewer deaths in the region early the the pandemic because of its younger population. But a second wave in late 2020 hit the region harder. Meanwhile, the U.K. COVID-19 variant, B.1.1.7, causes more hospitalizations among the young, and it is on the rise worldwide, increasing the urgency of vaccinating Africa. (The Guardian)

REQUIRED READING

Everything we know about the J&J COVID-19 vaccine pause so far - Chris Morris

If you just got the J&J vaccine, should you be worried? - David Z. Morris

White House says J&J pause won't slow vaccine rollout - Phil Wahba