Since the rollout of the AstraZeneca vaccine in January, more than a hundred cases of thrombosis have been linked to the jab worldwide. Thrombosis occurs when blood clots form in the veins or arteries which can then lead to swelling, chest pain, and in severe cases strokes and even heart attacks.
The global number of people who got blood clots after their COVID jab are just a drop in the ocean compared to millions who had no such side effects. But scientists have nevertheless been trying to figure out why this particular vaccine triggers dangerous blood clots.
So far, the different kinds of thrombosis that have been linked to the vaccine include deep vein thrombosis, portal vein thrombosis, and cerebral venous thrombosis (CVT).
Rare blood clot
In recent developments, scientists have figured out that a person’s blood group may play a major role in the formation of CVT—a rare blood clot that predominantly affects women.
According to The Telegraph, researchers from Royal Holloway, University of London examined 882 patients who were diagnosed with CVT in Europe. Their decade-long research showed that those with blood groups A, B or AB, were almost three times more likely to be susceptible to CVT than those with the blood group O. The study states:
Blood groups A, B, or AB, were at 2.85 times increased risk of CVT compared with individuals with blood group O.
Link to blood group
This may be because the human genome that connects with CVT is in the same location as the blood group gene. Pankaj Sharma, the director of the Institute of Cardiovascular Research at Royal Holloway said:
What we found is that the first genetic identification for susceptibility for CVT.
Their study has been published in the journal Annals of Neurology, and researchers are now hoping to extend their work to find out which blood groups were most affected by CVT after COVID vaccination.