Is THIS the link between AstraZeneca’s Covid vaccine and blood clots? Shot can trigger an immune response that in rare cases leads to the life-threatening side effect, research claims
- In Europe, about 30 cases of blood clots have been reported in people receiving a dose of AstraZeneca vaccine
- German researchers found signs of antibodies attacking platelets in the blood of nine people who developed blood clots after getting the injection
- These antibodies destroy the platelets and to make up for the loss, the body produces too many platelets, causing them to clot
- team says if their hypothesis is correct, the reaction can be identified and easily treated by a medical professional
- More than 20 European countries stopped using AstraZeneca’s injection this month for fear of clots, but then resumed use
- Officials in the EU ruled that the number of clots was no higher than in the general population
- But Canada took a break on Monday from using the vaccine for under-55s, citing concerns about blood clots
Researchers from Germany think they may have an explanation for the rare cases of blood clots reported in people who received the Oxford-AstraZeneca COVID-19 vaccine.
They say that in some cases the injection causes inflammation, forming antibodies against platelets, which cause blood to clot.
These antibodies destroy the platelets and to make up for the loss, the body produces too many platelets, causing them to clot.
The team says that if their hypothesis is correct, the reaction can be identified and easily treated by medical professionals.
It comes on the heels of the news that Canada is suspending use of the vaccine for people under 55 for fear of blood clots
German researchers found signs of a type of antibody that forms in response to inflammation in some people and attacks platelets in nine people who developed blood clots after receiving the AstraZeneca shot. These antibodies destroy the platelets and to make up for the loss, the body produces too many platelets, causing them to clot (resistant)
The researchers say the phenomenon is similar to a phenomenon rarely seen in a condition called heparin-induced thrombocytopenia (HIT) when patients take a drug called heparin.
Among those with HIT, the drug triggers the immune system to produce antibodies that activate platelets.
Drugs other than heparin can cause clotting disorders very similar to HIT, and researchers suspect that in rare cases the AstraZeneca vaccine may be another trigger.
Earlier this month, there were about 30 cases of blood clotting in patients after receiving a dose of the vaccine, with a few deaths as a result.
It led more than a dozen countries to stop using the vaccine, despite the European Medicines Agency saying the benefits of the injections outweighed the risks.
In a study published on Research square Monday ahead of peer review, the team is looking at nine cases of blood clots reported in Germany and Austria after receiving the AstraZeneca vaccine.
Seven patients had cerebral vein thrombosis (CVT), a blood clot in the brain; one had a pulmonary embolism and one had CVT had splanchnic venous thrombosis, which occurs when a vein in the abdomen clots.
Blood samples from four of the individuals showed that they had the same type of antibodies that activate platelets and initiate clotting at HIT.
These samples were then compared to 20 subjects who had received the AstraZeneca vaccine and had no blood clots.
None of these groups have these antibodies,
The researchers recommend that anyone who gets the AstraZeneca vaccine to watch for bruises, swelling, or headaches that start four or more days after immunization.
If vaccine recipients recognize any of these symptoms at an early stage, the situation can be easily treated by a doctor.
Meanwhile, a group of researchers in Norway say they have studied three cases of blood clots after the AstraZeneca vaccination.
Professor Pål Andre Holme from the University Hospital of Oslo told the Norwegian newspaper VG that he has come to the same conclusion, which is because antibodies cause an overreaction to the vaccine.
“Our theory that this is a strong immune response that most likely comes after the vaccine,” Holme said, according to one NPR translation.
“There is nothing but the vaccine that can explain this immune response.”