Johnson & Johnson on blood clot cases: ‘Insufficient’ evidence of ‘causal relationship’ between vaccine and cases

Johnson & Johnson scientists said on Friday that there’s currently “insufficient” evidence of a “causal relationship” between the company’s COVID-19 vaccine and the rare cases of blood clots that prompted a pause in distribution.

Company researchers wrote a letter to the editor of The New England Journal of Medicine published Friday that said “at this time, evidence is insufficient to establish a causal relationship between these events” and the Johnson & Johnson vaccine.

The researchers’ remarks followed after the CDC and FDA recommended a temporary halt in administering Johnson & Johnson vaccines, due to six cases, out of more than 6.8 million vaccinations, of cerebral venous sinus thrombosis (CVST) and low blood-platelet counts.

“CVST is a very rare health condition, and thus far, events reported in recipients of the … vaccine are occurring within the range of published background incidence,” the researchers wrote. “It is important to note that the incidence of CVST associated with low platelets is unknown and is considered by the FDA and the CDC to be extremely low.”

The vaccine manufacturer noted that in the clinical trial program when one case of CVST emerged, there was “no clear causality established.”