—Syncope and other anxiety-related events occur more often after receipt of Janssen COVID-19 vaccines than influenza vaccination, according to research published in the April 30 early-release issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.
Noting that on April 7, 2021, after five weeks of use of the Janssen COVID-19 vaccine, reports were received of clusters of anxiety-related events after vaccine administration from five vaccination sites, Anne M. Hause, Ph.D., from the CDC COVID-19 Response Team, and colleagues further investigated these cases. Site staff members were interviewed to gather additional information. While an investigation took place, four of the five vaccination sites temporarily closed.
The researchers found that among 8,624 Janssen COVID-19 vaccine recipients, there were 64 anxiety-related events overall, including 17 reports of syncope for vaccines administered during April 7 to 9, 2021. The prevalence of anxiety-related adverse events varied from 5.2 to 13.5 per 1,000 persons vaccinated at the five sites. On review of all reports, the Vaccine Adverse Event Reporting System reporting rate of syncope after the Janssen COVID-19 vaccination was 8.2 per 100,000 doses during March and April 2021. Reports of syncopal events were compared to those reported after influenza vaccine administration in the 2019 to 2020 influenza season; the reporting rate of syncope was 0.05 episodes per 100,000 doses of influenza vaccine.
“Increased awareness of anxiety-related events after vaccination will enable vaccination providers to make an informed decision about continuing vaccination,” the authors write.