 So what's the deal with COVID-19 vaccines and blood clots? So we've been hearing a lot about this in the media recently, and today the FDA put a hold on administration of the Johnson & Johnson COVID vaccine because of potential concerns of a specific type of blood clots, particularly something known as cerebrovenous sinus thrombosis. So the identified six patients, all young females, out of the 6.8 million folks who've gotten the Johnson & Johnson vaccine who've had this disorder. Now this is the same phenomenon that was noted out of Europe not too long ago with the AstraZeneca vaccine where about 30 folks had this diagnosis out of 20 million vaccines delivered. Now if you look at the statistics it's about one in a million chance that this is occurring with the vaccines. Now both the Johnson & Johnson and the AstraZeneca vaccine are of similar mechanism. They're both adenovirus vector vaccine. So when we're seeing this signal there is a concern that there could be something that's associated with the vaccines themselves. Now a little bit of background information. This CVST is different than traditional blood clots, right? So when you think of traditional blood clots like DVTs and PEs which are occurring in you know six to nine hundred thousand folks a year in the United States that's a more common scenario. This particular disorder is less common. It's thought to occur somewhere between five and 15 cases per million. So again it's pretty rare and we're actually seeing it even less frequently in these vaccinated population. Now the difference is the folks who are getting this after the vaccination also have something called thromocytopenia or low platelets and the coexistence of thromocytopenia and CVST is not common. So that's why they put a pause on this to try to figure out what's going on to see if this is a potential positive relationship. Now if anything this should give us confidence that the safety monitoring is robust and we're doing everything we should be doing to watch carefully for the safety of these vaccines. So I would applaud the FDA and CDC for you know implementing this and taking a deep dive into this even though it was a very very uncommon diagnosis that occurred. Now there could be some immune related mechanism that's occurring as a result of these particular vaccines where a very tiny percentage of folks are getting some sort of immune response against their platelets that's perhaps causing consumption activation of platelets that's leading to these problems. But again that's something that we're going to have to investigate and maybe hard to prove causality but we always want to practice precautionary principle. Now to note there are risk factors for getting CVST even independent of the vaccine. For example oral contraception this can increase the risk of this particular type of blood clot from 10 to 50 fold. Pregnancy itself can increase the risk other medical disorders such as cancer and even having COVID-19. In fact all those disorders I mentioned have a higher incidence of developing cerebral venous sinus thrombosis than this one in a million that we're seeing thus far with these particular vaccines. So what's going to happen now is the FDA is going to take a very close look at these particular cases these six cases and try to figure out was there a potential causative effect meaning could the vaccines have led to this and if so are there particular risk factors and concerns we should be aware of. So maybe we're going to be limiting the vaccine in a particular subset of patients a particular age group etc. This again is occurring in younger patients and mostly females which again fits the natural history of this disorder in that general population. But again the big picture is you're more likely to get COVID and die from COVID even if you're young rather than getting this particular disorder from the vaccines. Number two you're more likely to get stuck by lightning than you are to get this particular disorder from the vaccines and finally the overall safety profile of these vaccines and all the other vaccines is very good. Now for anybody who's already gotten the Johnson Johnson vaccine again this is all occurring within the first one to two weeks if you're more than two weeks out if you're probably safe and even if you're not remember the chances of this happening are uber low. Of note this has not been described in the mRNA vaccine that's the maternal advisor and we haven't seen those signals there. So at the end of the day just remember everything we do in medicine has a risk and a benefit. There is no medication no procedure that does not carry significant risk. I just explained to you before oral contraception has a much higher risk of developing free-moving sinus thrombosis than the COVID vaccine however you're not seeing a big uproar in the media about that. So we have to take it all in context. Let's see what the FDA has to say. If anything this should give us some comfort that the safety monitoring is robust it's doing what it's supposed to do. So in the end we're going to have to see what happens. My impression is that it is certainly possible if not probable there is a tiny risk of this problem happening with these vaccines and perhaps that's happening in a particular subset of patients. I do think we're going to be resuming these vaccines sooner than later but there may be some sort of restrictions or increased monitoring in certain populations. That's all for now and thanks for watching.