New Research Reveals Cause of Rare Blood Clots After COVID-19 Vaccines - NEJM (2026)
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 2026 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 vi...