Johnson & Johnson’s single-dose coronavirus vaccine was seen as a powerful tool to turn the tide in the global pandemic. But U.S. regulators on Tuesday called for a pause in the vaccine after six recipients developed a rare blood clot disorder.
The New York Times reported one woman died and a second in Nebraska has been hospitalized in critical condition.
All six recipients were women between 18 and 48 years of age.
The agencies said an advisory committee to the Centers for Disease Control and Prevention will meet on Wednesday to review the cases and the Food and Drug Administration will review the analysis. Both agencies said the adverse events appear to be extremely rare.
J&J said it is working closely with regulators. The drug maker said no clear causal relationship had been established between the events and its vaccine.
More than six million doses of Johnson & Johnson’s one-shot vaccine have been administered in the U.S.
The news sent J&J shares down in early trading Wednesday.
The agencies’ move comes one week after European regulators said they found a possible link between AstraZeneca’s vaccine and a rare blood clotting problem that had led to a small number of deaths. And just four days ago, the European Medicines Agency said it was reviewing rare blood clots in four people in the U.S who had received J&J’s vaccine.