FDA Strengthens Warning Over Severe Condition Linked to Johnson & Johnson’s COVID-19 Vaccine

U.S. drug regulators this week formally strengthened a warning to Americans regarding a severe condition linked to Johnson & Johnson’s COVID-19 vaccine.

Blood clots and low blood platelet levels, known as thrombosis with thrombocytopenia syndrome (TTS), are now listed as a contraindication, or a medical reason for somebody not to get the shot.

“Do not administer” the vaccine to individuals with a history of the set of conditions following the vaccine or any other adenovirus-vectored COVID-19 vaccine, the Food and Drug Administration (FDA) says in an updated fact sheet (pdf) for health care providers administering vaccines.

TTS has been reported in “a wide range of individuals 18 years and older” since administration of the Johnson & Johnson (J&J) vaccine began earlier this year, regulators say.

The highest reporting rate, approximately 1 case per 100,000 doses administered, has occurred in women aged 30 to 49.