the following explanation of the blood clots from J&J and astrazeneca vaccines from a doc at a discussion on medscape.com:
“What is common to the two COVID-19 vaccines recently observed to be associated with thrombotic thrombocytopenia (TT) are that they both use adenovirus as vectors-—AstraZeneka’s ChAd and J&J’s Ad26. Actually, adenovirus vectors have been long recognized to cause TT in both animal studies as well as in humans. Some strains of adenovirus (e.g., Ad5) can bind and activate platelets, which are then sequestered in the liver ( Stone et al, J Virology, 2007). One mechanism suggested for the activation of platelets is the role of von Willebrand factor and P-selectin in the platelet-leukocyte-endothelial interaction (Othman et al. Blood, 2006). It is not clear why such previous observations have not been noted earlier by the FDA and other agencies in their decision to give EUA for these vaccines.”
It’s called:
Virus induced thrombotic thrombocytopenia
https://scholar.google.com/scholar?q=Virus+induced+thrombotic+thrombocytopenia
<“What is common to the two COVID-19 vaccines recently observed to be associated with thrombotic thrombocytopenia (TT) are that they both use adenovirus as vectors”>
However, consider this excerpt from a Jan. 12 NYT report on the case of a Florida doctor who had taken the Pfizer mRNA vaccine:
“Dr. Gregory Michael, a 56-year-old obstetrician and gynecologist in Miami Beach, received the vaccine at Mount Sinai Medical Center on Dec. 18 and died 16 days later from a brain hemorrhage, his wife, Heidi Neckelmann, wrote in a Facebook post.
Shortly after receiving the vaccine, Dr. Michael developed an extremely serious form of a condition known as acute immune thrombocytopenia, which prevented his blood from clotting properly.”
The case of the doctor may have been very different, as it involved bleeding rather than blood clots. However, platelet problems were involved here, too.