Q&A on the Rare Clotting Events That Caused the J&J Pause
The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices voted on April 23 to resume the use of the Johnson & Johnson COVID-19 vaccine with a warning that it may cause a very rare, but dangerous blood clotting condition.
The 10 to 4 vote came 10 days after the CDC and Food and Drug Administration on April 13 recommended “a pause in the use” of the Johnson & Johnson COVID-19 vaccine “out of an abundance of caution,” due to six reports of a rare blood clot combined with low levels of blood platelets among more than 7 million J&J vaccines administered.
At the April 23 meeting, a CDC scientist presented nine additional reported cases, bringing the total confirmed cases to 15 out of nearly 8 million vaccine doses, as of April 21. Three of the 15 have died and four remain in intensive care.
We’ll take a look at these rare conditions, their frequency and the risks of COVID-19.
What do we know about the six cases, and have there been more since the pause was recommended on April 13?
The initial six cases were among 7.2 million J&J vaccines administered. They involved women, age 18 to 48, who suffered from a combination of a type of blood clot called cerebral venous sinus thrombosis, or CVST, and low levels of blood platelets, a condition known as thrombocytopenia.
The combination of blood clotting and, which help form clots to stop bleeding, “makes a pattern,” Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, in an April 13 press conference. And that pattern has similarly been reported in Europe in relatively few cases among the millions who have received the AstraZeneca vaccine.
