The researchers analyzed 100 patients who took adenovirus vaccines and developed VITT.
In early 2021, some patients were developing a rare yet life-threatening condition in which their blood would clot after getting a COVID-19 vaccine.
In these patients, their bodies were mistakenly attacking their own platelets, causing them to clump together and resulting in blood clots and low platelet counts. Researchers didn’t know why.
Now, a new study may offer an answer.
In a study published in The New England Journal of Medicine, researchers in Australia, Germany, and Canada analyzed 100 patients who took adenovirus vaccines and developed vaccine-induced immune thrombotic thrombocytopenia, also known as VITT.
They found that VITT was likely driven by a change in the antibodies, causing them to switch from harmless to harmful.
“This was the missing link that explains how a normal immune response can, in very rare cases, become harmful,” Jing Jing Wang from Flinders University said in a press release.
Harmful Antibodies
When the immune system encounters foreign invaders like viruses, bacteria, and vaccines, which mimic an infection, one way the body fights them off is to mass-produce antibodies.
These antibodies bind to the foreign invader, putting a target on its back so that other immune cells can kill it.
When patients were given the adenovirus vaccine, their bodies produced many antibodies that targeted components of the vaccine.
When antibodies are mass-produced, new changes are introduced to create the optimum antibody that can kill off invaders. In the case of VITT, some antibodies developed a single change that produced a harmful antibody instead.
Since some parts of platelets and adenoviruses share similarities, this single error made the new antibodies more likely to bind to platelets rather than adenoviruses.
“Exactly how or why this specific mutation occurs, I am not sure. It might all just be a random event,” Dr. Theodore Warkentin, a co-author of the study and professor emeritus of pathology and molecular medicine at McMaster University, told The Epoch Times.
These antibodies bind to platelets, forming a mini traffic jam inside blood vessels—essentially a blood clot.
By Marina Zhang
