The reason some people experience blood clots after receiving COVID-19 vaccines could be EDTA, a preservative found in AstraZeneca's vaccine, according to German hematologist Andreas Greinacher, MD.
AstraZeneca's vaccine contains more than 1,000 proteins derived from human cells, and EDTA helps them stay in the bloodstream. The proteins bind to a blood component called platelet factor 4 and then form structures that catalyze antibody production.
Dr. Greinacher explained his hypothesis to The Wall Street Journal May 13: When the body's immune response is kickstarted, the vaccine can trigger an ancient defense mechanism that spirals out of control and causes bleeding and clotting.
He is working to confirm his theory and hopes drugmakers will cooperate with his efforts so he can obtain greater access to their production processes.