US health agencies have recommended states pause administration of the Johnson & Johnson coronavirus vaccine, after reports of rare and severe blood clots emerged in six women. More than 6.8m doses have been administered nationally.
The concerns mirror those of drugs agencies in Europe and Australia over the AstraZeneca vaccine. That vaccine is not authorized in the US, and there have been no significant safety concerns raised about the two other vaccines that makeup the majority of US supply, from Pfizer-BioNTech and Moderna.
“People who have received the J&J vaccine who develop severe headache, abdominal pain, leg pain, or shortness of breath within three weeks after vaccination should contact their health care provider,” the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) said in a joint statement.
All six women were between the ages of 18 and 48. One woman died, and a woman in Nebraska is hospitalized in critical care, according to the New York Times. Johnson & Johnson’s vaccine is also under scrutiny by the European Medicines Agency, which is investigating four cases of clotting.
Because US states control their own health response, the health agencies framed their statement as a recommendation, even as federal sites will immediately pause administration of the vaccine.
The pause in administration of the Johnson & Johnson vaccine is certain to be a blow to the American immunization campaign, which was set to administer hundreds of thousands of easy to administer doses provided by the company.
Unlike vaccines developed by Pfizer and Moderna, Johnson & Johnson’s vaccine requires only one dose to provoke immunity, and can be stored in a common refrigerator. Both Pfizer and Moderna’s vaccine require ultra-cold storage and a two-dose regiment.
Health agencies said the blood clotting concern is “extremely rare”. That rarity may in fact be part of the concern, as it may make it more difficult to recognize and treat.
Federal regulators said they will convene an emergency meeting of vaccine regulators to discuss the matter, and a press conference was expected on Tuesday morning.
The pause is a blow to Johnson & Johnson, which only recently was forced to throw away between 13m and 15m doses of vaccine after a federal contractor botched doses.