Thread by @kurteichenwald

The key problem with @NateSilver538 tweets about J&J withdrawal is that it ignores the requirements of clinical trials and the potential impact of ignoring them, and instead relies on raw statistical analysis. The consequences of doing so could prove disastrous to the entire...1

...system of drug testing/regulation and end the ability for emergency authorization. (Note: I am conveying an expert's analysis, not my own.) The key element here is scientific mechanism. If these six had experienced something for which there was no theoretical mechanism for...2

...the problem (such as being diagnosed with cancer 5 days after the vaccine, something impossible to be linked to vaccine and which would simply be the consequence of large numbers/probabiliy of event) it would be ignored. But the possibility of blood clots does have a...3

...theoretical mechanism for how it is happening. Unlikely, but possible. However, it's more likely that these people had been COVID infected sometime before vaccination, possibly even months before, because COVID causes blood clots that can be silent until long after symptoms..4

...pass. Add to that, this is an emergency application grant. J&J results are still being tested - we have enough data to know that it is highly, highly safe, but all of the results still fall under the requirements of clinical trial. Six may not seem like a lot. But, if it...5

...is the consequence of the vaccine, again, unlikely, then there is no way of knowing if the clots only show up in the first week, if the problems of the clots are hidden for months, like with COVID, if it is a generalized clot problem or if in certain populations it is...6

...a higher statistical probability. For example, if 5 of the people with clots were African Americans over the age of 50 with hypertension and diabetes, the statistical impact is higher. If the cause of the clots is linked to the vaccine in that group, given that clots can....7

...be hidden for a long time, recipients in that cohort who had experienced nothing would be given a temporary prescription for blood thinners until they could be seen by a doctor & tested. Now, if instead the rules of drug testing were ignored, and they continued on without...8

...saying anything or analyzing what was happening, big problem: Data is public. Someone would see it. The public would know *anyway* about this. Add to that, news that the FDA/CDC had ignored the requirements under drug testing (and again, this is one giant test through....

...emergency authorization) *all* of the vaccines and every drug granted emergency authorization ever would be suspect. The entire system of drug authorization would collapse under the weight of destroyed credibility, because raw cost/benefit analysis rather than science was...

...used to make the decision. Then drug authorization would seem little different than Ford conducting a cost/benefit analysis on the Pinto, decide that the chance of explosion was minuscule compared to the number of cars on the road, and that they could just settle for less...

...cost (in this case, getting vaccines out) then it would take to fix or analyze the problem. Thats what Ford did: The Pinto is dead, and it took Ford decades to regain consumer trust. So now, raw statistical analysis is irrelevant. What is relevant is right now determining...

...if the vaccine itself is the cause of blood clots or if it is a consequence of COVID or the cruelty of large numbers, if there is a subset of a cohort that is at higher risk, if there is a long term clotting problem, or if there is nothing at all. The full expectation is...

...nothing at all. That is why there is a pause, and not a withdrawal - to give time for the work. And there is one thing people should take away from this: The vaccines are safe. They are watching this like hawks. When there is the slightest indication that there might be....

...a chance of an issue, they jump on it. That should give mass confidence on Pfizer and Moderna, and when (as it likely) J&J is back, it is safe. That should be the message and lesson.