Several mass vaccination sites in the USA have reported syncope and other anxiety-related adverse events in patients given Janssen's COVID-19 vaccine, according to a recent Morbidity and Mortality Weekly Report.
The five sites reported 64 such adverse events, including 17 cases of syncope, among 8624 vaccine recipients. Patient age was 18−77 (median 36) years; 61% were women. There were 13 patients who reported a history of needle aversion or fainting while receiving injections. The authors note that the single dose required for the Janssen vaccine may make it "a more attractive option for persons who have needle aversion" and it is therefore possible "that some persons seeking Janssen COVID-19 vaccination could be more highly predisposed to anxiety-related events after being vaccinated".
The most commonly reported event was dizziness/light-headedness (56%), followed by pallor/diaphoresis (31%), syncope (27%), nausea/vomiting (25%) and hypotension (16%); no events were classified as serious. Most events resolved within 15 minutes. For 4 of the sites, cases occurred on the first day they had administered the Janssen vaccine.
A search of the US FDA's Vaccine Adverse Events Reporting System (VAERS) database revealed 653 syncope reports between 2 March 2021 and 11 April 2021 among the 7.96 million vaccine recipients (8.2 per 100 000 doses). In comparison, there were 60 syncope reports among influenza vaccine recipients during the 2019-2020 season (0.05 per 100 000 doses).
Vaccine administrators need to be aware of anxiety-related events after vaccination, and all recipients should be observed for at least 15 minutes.
Reference
- Hause AM, et al. Anxiety-Related Adverse Event Clusters After Janssen COVID-19 Vaccination - Five U.S. Mass Vaccination Sites, April 2021. Morbidity and Mortality Weekly Report 70: 685-688, No. 18, 30 Apr 2021. Available from: URL: http://dx.doi.org/10.15585/mmwr.mm7018e3 [DOI] [PMC free article] [PubMed]