United States federal health agencies, yesterday, recommended pausing the use of Johnson & Johnson’s COVID-19 vaccine for at least a few days after six women under age 50 developed rare blood clots after receiving the shot, dealing a fresh setback to efforts to tackle the pandemic.
Johnson & Johnson (J&J) said it would delay rollout of the vaccine to Europe, a week after regulators there said they were reviewing rare blood clots in four recipients of the shot in the United States. J&J only began delivering its COVID-19 vaccine to European Union countries this week.
Acting U.S. Food and Drug Administration Commissioner, Janet Woodcock, said the agency expected the pause to be a matter of days, and was aimed at providing information to healthcare providers on how to diagnose and treat the clots.
The moves came after European regulators said earlier this month they had found a possible link between AstraZeneca’s COVID-19 vaccine and a similar rare blood clotting problem that led to a small number of deaths.
An advisory committee to the U.S. Centres for Disease Control and Prevention will meet today to review the cases, and the FDA will review the analysis, the agencies said in a statement.
All six cases involved women between the ages of 18 and 48, with symptoms occurring six to 13 days after vaccination.
The FDA said symptoms can arise three weeks after the shot and include severe headache, abdominal pain, leg pain or shortness of breath.
In the cases, a type of blood clot called cerebral venous sinus thrombosis was seen in combination with low levels of blood platelets, or thrombocytopenia.
J&J, whose shares were down two percent, said it was working closely with regulators and noted no clear causal relationship had been established between the clots and its vaccine.
J&J’s single-dose shot and AstraZeneca’s low-cost vaccine are seen as vital weapons in the fight against a pandemic that has claimed more than three million lives. But in the United States, vaccines from Moderna Inc and Pfizer Inc/BioNTech SE have accounted the vast majority of vaccinations so far.