The big news this morning is that the FDA is recommending an immediate pause on the use of the Johnson & Johnson COVID vaccine because of the same extremely rare but potentially fatal side effect which has led to limits on the AstraZeneca vaccine in Europe. Just in recent days the same J&J vaccine has also come under scrutiny in Europe because of the same side effect.
It is important to emphasize just how rare this side effect, a rare clotting disorder called cerebral venous sinus thrombosis, really is. The FDA is looking at 6 cases out of nearly seven million doses administered. When I discussed this issue a week ago TPM Reader JS noted that this level of risk would be roughly the same as you dying in an auto accident if you had to drive an hour or so to get your injection. Medical statisticians would likely say that even the binary comparison of “safe” and “unsafe” is misleading. It’s maybe more like the difference between a twenty minute drive to the supermarket with a functioning air bag in your car and one that’s not functioning. Still, though, some very small risk does seem to be there. Or at least the safety signal is strong enough that federal regulators want to call a halt to do more study.
Also of concern to federal regulators is that the standard treatment for a blood clot can make this disorder worse. So to the extent that this is going to be a known but extremely rare potential side effect federal regulators need to spread the word with doctors about how to identify and treat it.
All this said, if this pause becomes permanent or if the use of the J&J vaccine is significantly limited it is hard to imagine that it won’t lead to more deaths from COVID than those potentially saved by avoiding this rare side effect.
The vast majority of vaccinations in the US have been with the two-shot mRNA vaccines produced by Pfizer and Moderna. Combined they’ve been administered going on 200 million times, compared to about seven million for J&J. These are different vaccines but they use a common strategy and technology. Given their extremely strong safety record and efficacy at least as strong as every other known vaccine, it’s worth noting what a godsend these two vaccines are and what a breakthrough the mRNA technology is.