|Videos|April 19, 2021

COVID-19 Thrombotic Risk: Vaccines, The Virus, and Its Patients

A cardiology expert discusses the unique and currently investigated relationship between COVID-19, adenovirus vaccines, and thrombotic events.

Last week, a report on data from the Johnson & Johnson COVID-19 vaccine showed at least 6 young adult women given the one-shot product in the US experienced cerebral venous thrombosis.

The instances of rare thrombotic events, which triggered a federal and state-level pause of distribution with the vaccine as well as an emergency Advisory Committee on Immunization Practices (ACIP) meeting all last week, are yet to be associated with just 1 consistent trait among patients.

But experts have ideas of what may be driving risks.

In the second segment of an interview with sister publication HCPLive, Maja Zaric, MD, interventional cardiologist and assistant professor at Zucker Medical School, discussed some leading clinical theories as to what may be putting young women at risk of thrombotic events after receiving COVID-19 adenovirus vaccines including the Johnson & Johnson and AstraZeneca products.

Among the most prevalent factors may be young women’s “hormone matrix,” their use of birth control or even early pregnancy, or a smoking habit. All in all, it may speak to a need to prioritize vaccine distribution by thrombogeneicity risk—factors that could be easily applied to the pre-administration questionnaires included with such adenovirus vaccine doses.

“The overall benefit of the vaccines—including AstraZeneca and Johnson & Johnson—is significant,” Zaric explained. “But you have to measure it population-wise and the specifics of gender and age because of the other factors that could trigger clotting. It’s really important to set up some tentative rules for vaccination, then can distribute to older populations.”

Zaric also discussed the influence of thrombosis in patients infected with moderate-to-severe COVID-19—an outcome linked to symptoms becoming apparent days after early virus symptoms, and presenting almost identically to venous thromboembolism.

“The surprising phenomenon of COVID infection is that thrombotic event,” Zaric said. “It’s not typically seen in very early stages when the virus actively affects your upper respiratory system, and replicates rapidly. It doesn’t give more clinical presentation, but spreads more readily.”


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