None of the four companies have confirmed nor denied the report.
J&J researchers did state in NEJM that there is insufficient evidence to link six cases of cerebral venous sinus thrombosis (CVST) paired with low platelet counts to the company’s COVID-19 vaccine. Approximately seven million people in the U.S. have received the vaccine.
AstraZeneca (LON:AZN) is said to have been interested in allying with J&J to study vaccine benefits and risks. Pfizer and Moderna apparently didn’t. According to federal regulators, cases of CVST haven’t been observed in recipients of the Moderna and Pfizer vaccines.
Some physicians suspect that AstraZeneca’s ChAdOx1 nCoV-19 vaccine can lead to rare cases of acute thrombocytopenia and thrombosis, although a causal association has not been established, as another recent NEJM article concluded.
Last September, nine vaccine developers, including J&J, Pfizer and Moderna, pledged to ensure their vaccines were safe and effective before filing for regulatory authorization.
In the EU and U.K., blood clots affecting a small number of AstraZeneca recipients have led to constrained use of the ChAdOx1 nCoV-19 vaccine, which the company developed jointly with Oxford University.
Filed Under: Infectious Disease