Incidence of Blood Clot in Brain After Johnson & Johnson COVID-19 Vaccination

By JAMA Network Nov 1, 2021

At 11:00 a.m. ET today (Nov. 1, 2021), results will be released for research that has studied the incidence of blood clots in the brain following Johnson & Johnson/Janssen COVID-19 vaccination.

What the study did: Researchers compared post-Ad26.COV2.S (Johnson & Johnson/Janssen) vaccination rates for cerebral venous sinus thrombosis (CVST, a blood clot in the brain) with prepandemic rates to estimate CVST risk after vaccination. The extent of this rare side effect should be considered in the context of the vaccine’s effectiveness in preventing COVID-19.

Authors: Aneel A. Ashrani, MD, MS, of the Mayo Clinic in Rochester, Minnesota, is the corresponding author.

Link: JAMA Internal Medicine

Reference: November 1, 2021, JAMA Internal Medicine.
DOI: 10.1001/jamainternmed.2021.6352