Panic: Despite little evidence of risk, European countries pause AstraZeneca vaccine over blood clot fears

The consensus about this on political Twitter today is “this is crazy,” and so it is. It seems downright nutty by European leaders, not just needlessly delaying a vaccination effort that needs to speed up to avert a new disaster but destined to end up discouraging fencesitters from getting their shots.

The AstraZeneca vaccine was formerly known as the Oxford vaccine (it’s now commonly known by its manufacturer’s brand instead of its developer’s) and it’s in wide use across Europe. It hasn’t been approved in the U.S. yet since the FDA is still waiting on the results of clinical trials conducted here, but if all goes well AstraZeneca’s product will be added to America’s arsenal sometime next month. In other words, we’re getting more comfortable with the idea of using it at the very moment Europe’s getting less comfortable. Who’s right and who’s wrong?

Last week Denmark paused administration of the vaccine after one person developed blood clots and died after receiving a dose. Other small European countries began suspending its usage for the same reason. This afternoon the big dominoes began to fall — Germany, Spain, France, and Italy have all momentarily stopped dosing out the vaccine, and the European Medicines Agency will hold an “extraordinary meeting” on Thursday to assess the risk. There must be a lot of frightening blood-clot cases springing up to warrant grinding the continent’s vaccination machinery to a halt, especially at a moment when they’re desperate to beat back a new wave of COVID, huh?

Well, no. Hardly any cases at all, it turns out. AstraZeneca itself has looked at the data and seems puzzled about the panic:

So far across the EU and UK, there have been 15 events of DVT and 22 events of pulmonary embolism reported among those given the vaccine, based on the number of cases the Company has received as of 8 March. This is much lower than would be expected to occur naturally in a general population of this size and is similar across other licensed COVID-19 vaccines. The monthly safety report will be made public on the European Medicines Agency website in the following week, in line with exceptional transparency measures for COVID-19.

Furthermore, in clinical trials, even though the number of thrombotic events was small, these were lower in the vaccinated group. There has also been no evidence of increased bleeding in over 60,000 participants enrolled.

Just 37 cases — out of 17 million people vaccinated. One researcher in Britain, which is continuing to dose out AstraZeneca, told the AP he found the decision by some countries to suspend usage “baffling,” adding that “halting a vaccine rollout during a pandemic has consequences.” Other experts are reminding the public that correlation isn’t evidence of causation, especially when we’re talking about an incidence on the order of one out of every 450,000 cases.

“Vaccines protect against one thing: the infection or the infection plus disease,” said Susan Ellenberg, a biostatistician at the University of Pennsylvania who once tracked vaccine side effects at the FDA. “They don’t protect you against everything else that might possibly happen to you.”

That means that right after the vaccine is given to people, some will come down with cancer, or have heart attacks, or suffer falls. “There’s no reason to think that somehow there’s a magical period of time like, you know, four days or a week or two weeks after you get vaccinated, when none of those other horrible things are going to happen to you,” Ellenberg said.

We complain a lot about how hyper-cautious the CDC is but at least the CDC hasn’t spooked the country by slamming the brakes on vaccine distribution due to an unfounded panic about side effects rippling through the population. Even the WHO is nudging European leaders to knock it off and keep giving out AstraZeneca unless and until there’s a real reason to worry about their vaccine.

One reason there may be extra suspicion about the safety of AZ’s product is that the initial data was messy in certain ways. As I say, the U.S. has been cautious about approving it so far despite having many millions of doses stockpiled and ready to distribute. But I wonder if the deeper explanation for Europe’s willingness to pause isn’t the fact that vaccine hesitancy is higher there than it is here in the U.S. If you’re dealing with a population that’s already more skeptical of vaccines, you may feel pressure to take unusual measures to reassure them that it’s safe when they’re in doubt, like pausing distribution for a few days until regulators can look more deeply into this. If rumors are spreading among the public that AZ is causing blood clots, one might reason that the only way to beat back those rumors is to how that you’re taking them seriously.

It seems to me it might have the opposite effect as well, though. Formally pausing administration of the vaccines will lead skeptics to believe there’s enough to the rumors that the matter must be explored further, which, at a minimum, signals that regulators aren’t confident in the clinical data they’ve already reviewed. If Merkel’s willing to suspend AstraZeneca while her scientists look at the blood-clot evidence, why shouldn’t someone who’s iffy about getting vaccinated fear or even assume that experts may have overlooked some other frightening, as-yet-undiscovered side effect in their initial rush to get AZ approved? Skeptics are looking for excuses to distrust the vaccines and the institutions that have approved them. European governments are gift-wrapping one for them by treating flimsy evidence of unforeseen complications as evidence that they might have missed something important.

Is this some weird retaliation for Brexit, maybe, in which the AstraZeneca vaccine is deemed suspect by European leaders because of its Oxford pedigree? They’ll pay a steep price for such a petty gesture, if so:

Others have been quick to argue that if the EU is grandstanding against Brexit Britain for political gain, the consequences could be very serious. As the Economist journalist Stanley Pignal has tweeted: ‘If you vaccinate 100,000 people over the age of 50 today rather than tomorrow, you save 15 lives, according to a French analysis. Germany has 1.7m AstraZeneca doses that are now not being administered. Delay all of those by a week, you’re up 1,785 deaths.’

Again, it would be bad enough if they were pausing distribution for no good reason at a moment when the virus was spreading minimally. But Italy’s situation is sufficiently dire that they’re headed for another lockdown while Germany’s experts believe the country’s “third wave” has now begun. They’re going to suffer real pain for doing this despite without justification. As bad as the CDC has been throughout the pandemic in so many ways, you could plausibly argue that this decision is worse than anything that’s come from Washington.