Researchers say they may have found a cause for rare blood clotting that has occurred in some people who received the AstraZeneca COVID-19 vaccine. Anatolii Stepanov / AFP via Getty Images Hide caption
Anatolii Stepanov / AFP via Getty Images
Anatolii Stepanov / AFP via Getty Images
Two teams of European scientists, working independently of each other, believe they have identified the cause of a rare blood clotting disease that occurred in some people after receiving the AstraZeneca COVID-19 vaccine.
If this is correct, their research could mean that blood clots that do occur can be treated easily.
Earlier this month there were reports of about 30 blood clots after vaccination, some of which were fatal. This resulted in more than a dozen European countries stop using the AstraZeneca vaccine.
However, most of the countries have it after that European Medicines Agency conducted an investigation and stated Thursday that the AstraZeneca vaccine is safe and effective. The EMA said the vaccine’s benefits far outweigh the potential risks – pointing out that the rate of blood clots after the vaccine was actually lower than the expected rate in the general population.
Now a group of German researchers led by Professor Andreas Greinacher at the University of Greifswald said on Friday in one Explanation They believe that the AstraZeneca vaccine, in some cases, causes platelets in the blood to be overactivated, which can then cause potentially fatal blood clots. They said it was similar to a condition called Heparin-induced thrombocytopenia.
Greinacher and his colleagues analyzed the 13 cases of cerebral blood clots reported in Germany after about 1.6 million doses of the AstraZeneca vaccine had been administered in that country. Of the 13 cases, 12 were women and all cases occurred between four and 16 days after the shot was administered. The EMA had also found that almost all reported coagulation incidents occurred in women under the age of 55.
Greinacher and his colleagues say that in four of the patients they were able to isolate and identify the specific antibodies that trigger the immune response that leads to the cerebral blood clots.
While Greinacher and his colleagues were investigating the cases in Germany, researchers from Oslo University Hospital examined three blood clots after the vaccination in Norway. All Norwegian cases were healthcare workers under the age of 50. One of them has since died.
Professor Pål Andre Holme said that Norwegian newspaper VG He is confident that they have identified antibodies that were raised by the vaccine, which caused an overreaction of the immune system that resulted in blood clots.
“Our theory is that this is a strong immune response that is most likely to come after the vaccine,” said Holme. It is the same theory that Greinacher and his colleagues in Germany put forward.
“There is nothing but the vaccine that can explain this immune response,” he said.
Urged by the local newspaper as to why he is so confident, Holme added that “there is no other history in these patients that can elicit such a strong immune response. I am pretty sure these antibodies are the cause, and so.” I see no other reason. ” than that, it is the vaccine that triggers it. “
Not everyone, including the European Medicines Agency, is convinced that the cause of these clots has been found.
On Friday, the EMA announced that the risk of blood clots in people who received the AstraZeneca vaccine is “not increased”. The European regulator said it has so far reported 25 clots among the roughly 20 million people who received the AstraZeneca shot. However, the EMA did not completely rule out a possible link. “A causal link with the vaccine has not been established,” said the EMA in a statement, “but it is possible and deserves further analysis.”
The German researchers say the good news is that this rare side effect on the shock can be identified and treated if their theory is correct.
They say recipients should look out for any unusual bruising, swelling, or headache that starts four days or more after the vaccination. If identified quickly, the clotting problem can be treated relatively easily by health professionals.