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.

Johnson & Johnson is suspending sales forecasts for its COVID-19 vaccine only a few months after saying the shot could bring in as much as $3.5 billion this year.

A U.S. health panel said late Friday it’s time to resume use of Johnson & Johnson’s COVID-19 vaccine despite a very rare risk of blood clots.

Federal health agencies on Tuesday called for an immediate pause in use of Johnson & Johnson’s coronavirus vaccine after 6 people in the United States developed a rare disorder involving blood clots within about two weeks of vaccination, officials said.