COVID vaccine & Blood clots update: The European Medicines Agency @EMA_News has concluded that unusual blood clots with J&J vaccine are a very rare side effect.
The clots are very very rare (8 cases out of 7 million vaccinated in the US). ema.europa.eu/en/news/covid-…
The clots are very very rare (8 cases out of 7 million vaccinated in the US). ema.europa.eu/en/news/covid-…
The blood clots with J&J vaccine resemble clots seen with the Astra Zeneca vaccine. Both these vaccines are adenoviral vector based vaccines.
These unusual clots are:
-Very rare
-Cerebral venous or splanchnic
-Associated with low platelets
-Have high PF4 antibodies
These unusual clots are:
-Very rare
-Cerebral venous or splanchnic
-Associated with low platelets
-Have high PF4 antibodies
The risk estimates of these clots overall varies because we don't have full capture of numerator and denominator. What we know suggests risk:
~1 in 1 million with J&J
~1 in 250,000 with Astra Zeneca based on UK estimates
~1 in 100,000 with Astra Zeneca based on EU estimates.
~1 in 1 million with J&J
~1 in 250,000 with Astra Zeneca based on UK estimates
~1 in 100,000 with Astra Zeneca based on EU estimates.
Note that cerebral venous thrombosis has a baseline rate of about 1 in 250,000 even without the vaccine. COVID itself causes cerebral venous thrombosis at a much higher rate.
The benefits of J&J vaccine and Astra Zeneca vaccine far outweigh the risks in everyone over age 30.
The benefits of J&J vaccine and Astra Zeneca vaccine far outweigh the risks in everyone over age 30.
The temporal relationship to the vaccine and the unusual combination of cerebral venous (Or splanchnic venous) thrombosis along with very low platelets is what causes the concern for a real link to the vaccine.
These clots resemble ones we sometimes see after use of heparin.
These clots resemble ones we sometimes see after use of heparin.
We now have an idea of the mechanism. We will be able to diagnose these clots sooner, and manage them better. So I think outcomes will improve significantly if and when these very rare clots do occur.
I strongly urge people to get whichever vaccine you are offered. All are highly effective. COVID is 100 times worse than any side effect of the vaccine.
If you are less than 30, discuss with your doctor, unless such decisions have been made already at the national level.
If you are less than 30, discuss with your doctor, unless such decisions have been made already at the national level.
For more details on the mechanism by which these clots occur see thread below.
https://twitter.com/VincentRK/status/1381357909880283136
There is no risk of these unusual clots with mRNA vaccines, either Pfizer or Moderna.
Clearly after 120 million people have been vaccinated in the US with those two vaccines, we have a good idea of how incredibly safe they are.
Clearly after 120 million people have been vaccinated in the US with those two vaccines, we have a good idea of how incredibly safe they are.
Some people ask why didn't we catch the risk of the clots with the randomized trials.
Given the rarity of these clots, we would have needed randomized trials of a million people to find such ultra rare events. So unfortunately these type of events are only detected post-approval
Given the rarity of these clots, we would have needed randomized trials of a million people to find such ultra rare events. So unfortunately these type of events are only detected post-approval
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