https://www.nytimes.com/2021/02/08/health/immune-thrombocytopenia-covid-vaccine-blood.html
Hematologists with expertise in treating immune thrombocytopenia said they suspected that the vaccine did play a role. But they said that cases after vaccination were likely to be exceedingly rare, possibly the result of an unknown predisposition in some people to react to the vaccine by developing an immune response that destroys their platelets. The disorder has occurred, rarely, in people who received other inoculations, particularly the measles-mumps-rubella one.
In its most common form, immune thrombocytopenia is an autoimmune disease that affects about 50,000 people in the United States, according to a support group for patients. The condition develops when the immune system attacks platelets or the cells that create them, for unknown reasons. It sometimes follows a viral illness, and can persist for months or become chronic and last for years. It is generally treatable. Professional groups have advised that patients with the disorder be vaccinated for Covid, but after consulting with their hematologists.
