Following up on Ed’s post earlier about today’s big news, the divide between doctors/scientists on the one hand and average joes like me about the wisdom of pausing distribution of J&J is even starker than usual on social media. There are plenty of experts who think the caution is prudent and justified. There are hardly any laymen who agree.

Although, interestingly, it’s not uniform among the pros. Even some of them think the FDA’s move was shortsighted.

Those in favor of pausing include some of the most closely public-health experts on Twitter:

Important breaking news

US govt calling for a pause of the J&J vaccine after a small number of people develop a very rare blood clot.

While unfortunate, its the right step.

Central to vaccination success is ensuring people have confidence they are safehttps://t.co/pnyNnbvHjm

— Ashish K. Jha, MD, MPH (@ashishkjha) April 13, 2021

I know lots of folks think this will cause more vaccine hesitancy — and more harm than good.

I'm honestly not so sure

My sense is confidence comes from people believing that we have a vigorous system that takes adverse events seriously.

We do.

This is how it works.

— Ashish K. Jha, MD, MPH (@ashishkjha) April 13, 2021

👇🏻Exactly.
6 cases out of 7 million doses.

This is an extremely rare (less than 1 in a million) “safety signal.” Its normal for FDA to investigate, and to pause while it does out of caution.

I got the J&J vaccine 8 days ago. I’m not losing sleep over this. https://t.co/J56BtGSCG3

— Dr. Angela Rasmussen (@angie_rasmussen) April 13, 2021

– The risk-benefit profile depends upon age, likely sex, and population incidence
– As we’ve seen in Europe, one path forward may be vaccination policies that vary by age, sex
– Understanding the causal mechanism may help us develop targeted policies and potential treatments
2/2

— Natalie E. Dean, PhD (@nataliexdean) April 13, 2021

It’s not a long “pause” either. The FDA will meet tomorrow about it. “[I]f you want vaccine-hesitant people to believe no corners were cut, you can’t then go around very obviously cutting corners,” said one Twitter pal in support of the delay. Which is a defensible argument: Imagine if the FDA simply said “the clots are super-rare, we’re sure it’s fine,” without any further investigation — and then a dozen more clots were reported in J&J recipients. What would the public’s view of that vaccine be then?

Other doctors think the FDA’s being overcautious, particularly given the urgency of getting people vaccinated ASAP before we endure another national wave. The risk of blood clots from vaccination can’t be taken in isolation; it needs to be compared to two other risks. First, what’s the risk of a person developing clots for “normal” non-vax reasons? And second, what’s the risk of an unvaccinated person contracting COVID and either dying from it or developing COVID-related blood clots? Dr. Megan Ranney ran the numbers:

4. Let’s compare: Which is higher?

— Megan Ranney MD MPH 🗽 (@meganranney) April 13, 2021

6. What is INDUBITABLY true right now is that #covid19 cases are rising in the US and across the world, and the J&J vaccine is very very good at preventing disease / excellent at preventing severe disease and death.

— Megan Ranney MD MPH 🗽 (@meganranney) April 13, 2021

Note the last point, though. Many skeptics have cited the fact that there were only six clotting cases out of seven million doses, making the odds literally one-in-a-million of this happening to a J&J recipient. (Slightly more, actually.) But that’s only true if the risk is spread equally among all recipients, which may not be the case. There’s chatter today about the fact that all six patients were women, and all of childbearing age. A friend speculated this morning to me that this may be a case of the vaccine interacting badly with birth control, which seems plausible on its face as certain forms of contraception *do* increase the risk of blood clots. In which case, it may be that J&J is perfectly safe for men and for older women — but a bit riskier than one-in-a-million for younger women.

Especially since we don’t know for sure how many clotting cases there are. Six have been confirmed, but there may be more that went overlooked by doctors who treated clot patients recently because they weren’t looking for a connection between clotting and J&J’s vaccine. Now they’ll be on the lookout.

There’s a massive third risk created by pausing J&J, of course. Remember what happened to public trust in AstraZeneca’s vaccine last month when European governments temporarily paused distribution due to clotting fears?

Inescapably, some people who are on the fence about getting vaccinated will treat the FDA’s “pause” as proof that the vaccines aren’t safe and decide against getting their shot. And not just J&J’s vaccine, maybe: The fact that super-ultra-rare blood clots weren’t discovered during that company’s clinical trials will lead anti-vaxxers to make the leap that there may be super-ultra-rare side effects from the Pfizer and Moderna vaccines that are still undiscovered. (Although, interestingly, there wasn’t much spillover to opinion about the other vaccines in the poll above due to doubts about AstraZeneca.) Anecdotal reports of newfound vaccine hesitancy are already circulating on social media:

We've already heard from two friends this morning — unsolicited — that this J&J stoppage has convinced them the vaccines were rushed and can't be trusted.

Heckuva job.

— Tim Alberta (@TimAlberta) April 13, 2021

The “pause” could theoretically save, say, five lives by preventing vax-related blood clots and cost a thousand lives by inadvertently convincing people who would otherwise have gotten vaccinated that the scientists really did “cut corners” in this process and their products can’t be trusted. That’s some trade. And that’s why laymen are so angry about today’s decision: For us, the main consideration here is avoiding anything that might encourage vaccine hesitancy unless the data is compelling that there’s a meaningful risk of harm involved. And there isn’t yet.

Although doubtless the FDA would say, “Well, that’s why we need to pause and investigate.”

Watch Scott Gottlieb’s characteristically balanced take this morning on CNBC. He urges people not to overreact but acknowledges that the decision comes with costs, and not just increased vaccine hesitancy. Remember that the J&J vaccine is hardier than Pfizer’s or Moderna’s, says Gottlieb, and therefore was being eyed for deployment to more rural areas where the deep-freeze storage needed for the mRNA vaccines isn’t as widely available. The fact that J&J is a single dose also made it better suited to rural residents, who tend to be more vaccine-resistant than city-dwellers and need to travel longer distances to get their shots. With J&J temporarily paused, the mRNA vaccines will now have to be sent to those rural areas instead. Can they be stored safely there? How many locals will balk at two doses? It’s a bad situation.

"Let's start with what the FDA didn't do: they didn't revoke the EUA, they didn't order this off the market. This was a requested pause which is an awkward regulatory step but it reflects a level of caution not to appear too forcefully here," says @ScottGottliebMD on $JNJ vaccine pic.twitter.com/42Fg8OX8Ra

— Squawk Box (@SquawkCNBC) April 13, 2021