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Vaccine Blood-Clot Side Effect Puts Focus on Immune Reaction

  • FDA, CDC make joint recommendation for pause on J&J shot
  • Combination of low platelets with clotting seen in few people
Bloomberg business news
WATCH: U.S. health officials called for an immediate pause in using Johnson & Johnson’s single-dose Covid-19 vaccine after six women who received it developed a rare and severe form of blood clotting. (Source: Bloomberg)
Updated on

Rare cases of clotting that have been seen with two Covid-19 vaccines have put the spotlight on an uncommon reaction that occurs when the body unleashes its immune firepower against blood platelets.

Health officials are exploring whether and how the immune reaction may occur in people who have received vaccines made by AstraZeneca Plc and Johnson & Johnson. Concerns have risen so high that the U.S. Centers for Disease Control and Prevention and Food and Drug Administration jointly recommended a pause in the use of the J&J vaccine on Tuesday.