The U.S. Food and Drug Administration (FDA) said on Thursday it was limiting the use of Johnson & Johnson's COVID-19 vaccine for adults due to the risk of a rare blood clotting syndrome.

The J&J shot is authorized for those aged 18 and above and is one of the three COVID-19 vaccines cleared for use in the United States.

The agency said the J&J shot can be administered in cases where authorized or approved COVID-19 vaccines are not accessible or if an individual is less keen on using the other two shots.

The FDA said its analysis had determined that the risk of thrombosis with thrombocytopenia syndrome after the administration of the shot warrants limiting of the authorization.

J&J did not immediately respond to a Reuters request for comment.

(Reporting by Amruta Khandekar; Editing by Anil D'Silva)