One US patient died, another critical after J&J vaccine: Official

One US patient died from blood clotting complications after receiving the Johnson & Johnson Covid vaccine while another is in critical condition, a senior scientist for the Food and Drug Administration said Tuesday.

Overall, six women aged between 18 to 48 developed a rare form of brain blood clotting with low blood platelets between six and 13 days after receiving the shot.

"One case was fatal, and one patient is in critical condition," Peter Marks said in a call with reporters.

Marks drew a link with a similar disorder seen in Europe after people received the AstraZeneca vaccine, which is also based on adenovirus vector technology.

The illness is thought to derive from a rare immune response to the vaccines that triggers the activation of clots.

Anne Schuchat, a senior official with the Centers for Disease Control and Prevention, added that the risk was very low for people who had received the vaccine a month or more ago.

"For people who recently got the vaccine within the last couple of weeks, they should be aware to look for any symptoms.

"If you've received a vaccine and develop severe headaches, abdominal pain, leg pain, or shortness of breath, you should contact your health care provider," she added.