Cardiac Adverse Events after Vaccination—A Systematic Review

The Vaccine Adverse Event Reporting System database has been used to report adverse events following several vaccines. We studied the patient population predisposed to such reactions and how these reactions differ with respect to the vaccine type. We searched the electronic databases PubMed, EMBASE, and Scopus up to 9 July 2021 for any study describing cardiac adverse events attributed to the vaccination. A total of 56 studies met the criteria comprising 340 patients. There were 20 studies describing cardiac adverse events following smallpox vaccination, 11 studies describing adverse events after influenza vaccination, and 18 studies describing adverse events after COVID-19 vaccination. There was a total of six studies describing cardiac adverse events after the pneumococcal vaccine, tetanus toxoid, cholera vaccine, and rabies vaccine. Adverse events following influenza vaccination occurred more commonly in older females within an average duration of four days from vaccination. Pericardial involvement was the most reported adverse event. Adverse events following COVID-19 vaccination happened at a mean age of 42.7 years, more commonly in males, and mostly after a second dose. Adverse events following smallpox vaccination occurred more commonly in younger males, with an average onset of symptoms from vaccination around 16.6 days. Adverse events were mostly myopericarditis; however, the acute coronary syndrome has been reported with some vaccines.

Myopericarditis Associated With Smallpox Vaccination Among US Army Personnel - Fort Hood, Texas, 2018

OBJECTIVE

In March 2018, the US Department of Defense (DOD) added the smallpox vaccination, using ACAM2000, to its routine immunizations, increasing the number of persons receiving the vaccine. The following month, Fort Hood reported a cluster of 5 myopericarditis cases. The Centers for Disease Control and Prevention and the DOD launched an investigation.

METHODS

The investigation consisted of a review of medical records, establishment of case definitions, causality assessment, patient interviews, and active surveillance. A 2-sided exact rate ratio test was used to compare myopericarditis incidence rates.

RESULTS

This investigation identified 4 cases of probable myopericarditis and 1 case of suspected myopericarditis. No alternative etiology was identified as a cause. No additional cases were identified. There was no statistically significant difference in incidence rates between the observed cluster (5.23 per 1000 vaccinated individuals, 95% CI: 1.7-12.2) and the ACAM2000 clinical trial outcomes for symptomatic persons, which was 2.29 per 1000 vaccinated individuals (95% CI: 0.3-8.3).

CONCLUSIONS

Vaccination with ACAM2000 is the presumptive cause of this cluster. Caution should be exercised before considering vaccination campaigns for smallpox given the clinical morbidity and costs incurred by a case of myopericarditis. Risk of myopericarditis should be carefully weighed with risk of exposure to smallpox.

Smallpox Vaccination-Associated Myopericarditis

Myopericarditis related to a smallpox vaccination often goes unrecognized and untreated because physicians are not routinely screening for vaccination administration.