Patients vaccinated against COVID-19 faced a 59 percent lower risk of both venous thromboembolism and death within 30 days of infection, according to new research — evidence arriving as COVID-19 vaccine guidance continues to shift.
According to Drug Topics' November 2 report, the study, published in Research and Practice in Thrombosis and Haemostasis, drew on national research from the National Clinical Cohort Collaborative database. Among hospitalised patients, COVID-19 carried a greater risk of blood-clot events than influenza, the report noted, citing earlier coverage: compared with patients hospitalised with flu during the 2018–2019 season, those hospitalised with COVID-19 were more likely to develop deep vein thrombosis or pulmonary embolism within 90 days, both before and after vaccines became available.
But the elevated risk of blood clots and mortality was most acute during the early Ancestral and Delta waves, the study found. During the contemporary Omicron era, COVID-19's clinical risk profile converged with that of non-COVID acute respiratory infections, particularly among vaccinated individuals.
Large-scale observational data from the IVY Network further indicated that completing an original monovalent mRNA vaccination series offered 84 percent effectiveness in preventing COVID-19 hospitalisations associated with acute venous thromboembolism, the report said.
The findings arrive at a crucial moment, Drug Topics noted, as the CDC and the Advisory Committee on Immunization Practices have transitioned COVID-19 vaccine guidance for adults and children from universal recommendations to a shared clinical decision-making framework.
What happens next: pharmacists and clinicians navigating the new shared-decision framework can point to the clot and mortality data as part of conversations with patients weighing vaccination.