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. 2023 Feb 1;7(1):e55.
doi: 10.1017/cts.2022.527. eCollection 2023.

COVID-19 vaccination and venous thromboembolism risk in older veterans

Peter L Elkin  1   2 , Steven H Brown  2 , Skyler Resendez  1 , Wilmon McCray  1 , Melissa Resnick  1 , Kendria Hall  1 , Gillian Franklin  1 , Jean M Connors  3 , Mary Cushman  4
Affiliations

COVID-19 vaccination and venous thromboembolism risk in older veterans

Peter L Elkin et al. J Clin Transl Sci. .

Abstract

Introduction: It is important for SARS-CoV-2 vaccine providers, vaccine recipients, and those not yet vaccinated to be well informed about vaccine side effects. We sought to estimate the risk of post-vaccination venous thromboembolism (VTE) to meet this need.

Methods: We conducted a retrospective cohort study to quantify excess VTE risk associated with SARS-CoV-2 vaccination in US veterans age 45 and older using data from the Department of Veterans Affairs (VA) National Surveillance Tool. The vaccinated cohort received at least one dose of a SARS-CoV-2 vaccine at least 60 days prior to 3/06/22 (N = 855,686). The control group was those not vaccinated (N = 321,676). All patients were COVID-19 tested at least once before vaccination with a negative test. The main outcome was VTE documented by ICD10-CM codes.

Results: Vaccinated persons had a VTE rate of 1.3755 (CI: 1.3752-1.3758) per thousand, which was 0.1 percent over the baseline rate of 1.3741 (CI: 1.3738-1.3744) per thousand in the unvaccinated patients, or 1.4 excess cases per 1,000,000. All vaccine types showed a minimal increased rate of VTE (rate of VTE per 1000 was 1.3761 (CI: 1.3754-1.3768) for Janssen; 1.3757 (CI: 1.3754-1.3761) for Pfizer, and for Moderna, the rate was 1.3757 (CI: 1.3748-1.3877)). The tiny differences in rates comparing either Janssen or Pfizer vaccine to Moderna were statistically significant (p < 0.001). Adjusting for age, sex, BMI, 2-year Elixhauser score, and race, the vaccinated group had a minimally higher relative risk of VTE as compared to controls (1.0009927 CI: 1.007673-1.0012181; p < 0.001).

Conclusion: The results provide reassurance that there is only a trivial increased risk of VTE with the current US SARS-CoV-2 vaccines used in veterans older than age 45. This risk is significantly less than VTE risk among hospitalized COVID-19 patients. The risk-benefit ratio favors vaccination, given the VTE rate, mortality, and morbidity associated with COVID-19 infection.

Keywords: EHR data; Vaccination; data science; informatics; venous thromboembolism.

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Conflict of interest statement

The authors have no conflict of interest to declare.

References

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    1. Janssen FDA EUA.pdf [Internet]. (https://www.fda.gov/media/146303/download)

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