On Thursday, the US Food and Drug Administration limited the use of Johnson & Johnson′s COVID-19 vaccine for adults due to the risk of a rare blood clotting syndrome.

The Food and Drug Administration said the J&J shot was approved in the United States in February 2021 for adults and could be used in situations where authorized or approved COVID-19 vaccines are unavailable or if a person is unwilling to use the other two shots, but warned that the risk of TTS warranted caution.

The US Centers for Disease Control and Prevention recommended in December that Americans may select Pfizer and Modernas mRNA doses over J&J′s vaccine because of the risks of thrombosis. According to the CDC, 18.7 million J&J COVID-19 vaccines had been administered, compared to 217.5 million Moderna vaccines and 340.6 million Pfizer vaccines.

J&J has amended the COVID-19 vaccination fact sheet in the United States to include a warning regarding the risk of thrombosis associated with thrombocytopenia syndrome (TTS), a rare but potentially fatal illness. 

The FDA updated the J&J vaccine fact sheet in January to highlight the risk of immune thrombocytopenia; months after the European Unions drug agency did the same. (Reuters, May 6, 2022)