FDA restricts J&J's COVID vaccine due to clot risk

U.S. regulators are strictly limiting who can receive Johnson & Johnson's COVID-19 vaccine due to a rare but serious risk of blood clots. FDA said Thursday the shot should only be given to adults who cannot receive a different vaccine or specifically request J&J's vaccine.

The decision is the latest restriction to hit the company's vaccine, which has long been overshadowed by the more effective shots from Pfizer and Moderna. In December, the Centers for Disease Control and Prevention recommended prioritizing the Moderna and Pfizer shots over J&J's because of its safety issues. Under the new FDA instructions, J&J's vaccine could still be given to people who had a severe allergic reaction to one of the other vaccines and can't receive an additional dose. The clotting problems first came up last spring, with the J&J shot in the U.S. and with a similar vaccine made by AstraZeneca that is used in other countries. The rollout of the company's vaccine was hurt by a series of troubles, including manufacturing problems at a Baltimore factory that forced J&J to import millions of doses from overseas. Additionally, regulators added warnings about the blood clots and a rare neurological reaction.