Increased risk of CVST with thrombocytopenia in J&J COVID-19 vaccine recipients

From March 2 to April 21, 2021, after receiving the COVID-19 vaccine Ad26.COV2.S (Janssen / Johnson & Johnson), a case series reported 12 cases of cerebral venous sinus thrombosis (CVST) with thrombocytopenia reported in JAMA.

The Ad26.COV2.S COVID-19 vaccine uses a human adenoviral vector and received emergency use approval on February 27, 2021. In Europe, the ChAdOx1 nCOV-19 vaccine (Oxford / AstraZeneca), which uses a chimpanzee adenoviral vector, has been associated with CVST with thrombocytopenia.

After 6 cases of CVST with thrombocytopenia in approximately 7 million recipients of the Ad26.COV2.S vaccine in the United States, the Centers for Disease Control and Prevention and the Food and Drug Administration recommended a hiatus in the use of the Vaccine. As of April 21, 6 additional cases of CVST with thrombocytopenia had been reported to the Vaccine Adverse Event Reporting System.

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The case series included 12 recipients of the Ad26.COV2.S vaccine that was diagnosed with CVST and thrombocytopenia from March 2 to April 21, 2021. The aim was to report the clinical course, imaging findings, laboratory tests, and post-diagnosis results.

All 12 cases of CVST and thrombocytopenia occurred in women under 60 years of age. The mean interval from vaccination to onset of symptoms was 8 days and ranged from 6 to 15 days. Presentation headaches were reported in 11 out of 12 women. One patient initially had back pain and later headache.

Intracerebral bleeding was reported in 7 patients and non-CVST thrombosis in 8 women. The platelet nadirs ranged from 9 × 103 / μl to 127 × 103 / μl.

All enrolled patients were hospitalized and 10 were admitted to an intensive care unit (ICU). Providers gave heparin to 6 patients diagnosed prior to the public announcement of CVST and thrombocytopenia events, and all were subsequently exchanged for a non-heparin anticoagulant. 4 patients initially received a nonheparin anticoagulant for CVST treatment, while 2 patients received no anticoagulants.

All antibody test results were positive in the 11 patients with heparin platelet factor 4 enzyme-linked immunosorbent assay (ELISA), heparin-induced thrombocytopenia (HIT).

At the time of the final follow-up, 3 patients died, all of whom had intraparenchymal hemorrhage and evidence of a mass effect on initial head imaging. In addition, 3 patients continued intensive care, 2 continued hospitalization outside the intensive care unit, and 4 were discharged home.

As of April 21, 2021, 2 additional US reports of CVST with thrombocytopenia after administration of Ad26.COV2.S have been confirmed.

The case series had several limitations, including the retrospective design of medical records review, lack of data on laboratory tests, and the use of data from a passive surveillance system with possible underreporting of CVST with thrombocytopenia.

“This case series may influence clinical guidance on the resumption of Ad26.COV2.S vaccination in the US and the investigation of the possible relationship between Ad26.COV2.S vaccine and CVST with thrombocytopenia,” the study’s researchers concluded.


See I, Su JR, Lale A, et al. US case reports of cerebral venous sinus thrombosis with thrombocytopenia after Ad26.COV2.S vaccination, March 2 to April 21, 2021. JAMA. 2021. Published online April 30, 2021. doi: 10.1001 / jama.2021.7517

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