High Incidence of CVST Observed 15 Days After COVID-19 Vaccination

Aneel A. Ashrani, MD

Recent data have suggested a possible association between the Ad26.COV2.S (Johnson & Johnson) COVID-19 vaccination and cerebral venous sinus thrombosis (CVST). Accordingly, a comparison of age- and sex-specific CVST rates after Ad26.COV2.S vaccination with the prepandemic CVST rate was performed in a recent study.

Led by Aneel A. Ashrani, MD, MS, Division of Hematology, Department of Internal Medicine, Mayo Clinic, investigators observed the CVST incidence rate 15 days after Ad26.COV2.S vaccination was significantly higher than the pre-pandemic rate.

Methods

The population-based cohort study estimated the risk of CVST after Ad26.COV2.S vaccination through identification of CVST in Minnesota from January 2001 - December 2015.

Then, investigators used CDC Vaccine Adverse Event Reporting System (VAERS) data from the vaccination approval in February 2021 until May 2021 in order to estimate incidence of CVST after Ad26.COV2.S vaccination. They assumed 3 plausible post vaccination periods (15, 30, and 92 days) during which individuals were considered to be at risk of CVST.

Following that, investigators compared post-Ad26.COV2.S vaccination CVST rates with pre pandemic rates in order to estimate postvaccination CVST risk.

Findings

Data show 39 Olmsted County residents developed acute incident CVST from 2001 through 2015, where a total of 29 patients (74.4%) had a predisposed venous thromboembolism risk factor within 92 days before the event.

At diagnosis, the median age was 41 years and 22 residents with CVST (56.4%) were female. Overall age- and sex-adjusted CVST incidence was 2.34 per 100,000 person-years (95% CI, 1.60 - 3.08). Data show age-adjusted CVST rates for females were 2.46 per 100,000 PY (95% CI, 1.22 - 3.46) and 2.34 per 100,000 PY (95% CI, 1.22 - 3.46) for males.

Investigators observed men aged 65 years or older had the highest CVST rate (6.22 per 100,000 PY; 95% CI, 2.50 - 12.82), followed by women aged 18 - 29 years (4.71 per 100,000 person-years; 95% CI, 2.26 - 8.66).

Overall incidence rates of post-Ad26.COV2.S vaccination CVST was 8.65 per 100,000 PY (95% CI, 5.88 - 12.28) at 15 days, 5.02 per 100,000 PY (95% CI, 3.52-6.95) at 30 days, and 1.73 per 100,000 PY (95% CI, 1.22 - 2.37) at 92 days.

Additionally, the 15-day postvaccination CVST incidence rate for females was 13.01 per 100,000 PY (95% CI, 8.24 - 19.52), while it was 4.41 per 100,000 PY (95% CI, 1.90 - 8.68) for males. This was 5.1-fold higher for females when compared with the pre-COVID rates (13.01 versus 2.5 per 100,000 PY, P <.001).

Takeaways

“However, the higher rate of this rare adverse effect must be considered in the context of the effectiveness of the vaccine in preventing COVID-19 (absolute reduction of severe or critical COVID-19 of 940 per 100,000 PY,” investigators wrote.

The study, “Age- and Sex-Specific Incidence of Cerebral Venous Sinus Thrombosis Associated With Ad26.COV2.S COVID-19 Vaccination,” was published in JAMA Internal Medicine.