That’s about half as likely as getting struck by lightning in a year. These six cases all occurred in women ages 18-48, and from 6 to 13 days after vaccination. How many people have experienced this possible reaction?Īs of April 13, 2021, about one in a million: Six cases out of the 6.8 million doses of the J&J vaccine administered in the U.S. It is important to note that this disorder, called vaccine-induced immune thrombotic thrombocytopenia, is not a problem with the mRNA-based Pfizer and Moderna COVID-19 vaccines. This antibody causes the clotting disorder by activating platelets to clot. In the case of the AstraZeneca vaccine, the clotting disorder has been linked to antibodies against platelet factor 4 (PF4) that are apparently induced by the adenovirus backbone of the vaccine. This same side effect has been seen in the AstraZeneca COVID-19 vaccine that also uses an adenovirus to deliver the coronavirus spike glycoprotein. In the vaccine-associated cases of this, platelets in blood, which are important for making clots, have been lower than normal. This is called central venous sinus thrombosis. The potential side effect is a blood clot in the veins that drain blood from the brain. What is this potential side effect of the J&J vaccine for COVID-19? William Petri, an infectious disease physician and immunologist at the University of Virginia School of Medicine, answers questions to help put this development in context. The clotting, which resulted in one woman’s death, led the CDC and FDA on April 13, 2021, to pause use of the J&J vaccine.

It delayed voting on a recommendation to the CDC so that members can further evaluate risk and data. The panel, the Advisory Committee on Immunization Practices, or ACIP, advises the Centers for Disease Control and Prevention on immunization. A panel of experts met on April 14, 2021, to review evidence on blood clots that have been reported in seven people after they received the one-dose Johnson & Johnson COVID-19 vaccine.

Cdc pauses johnson and johnson vaccine