COVID-19 Vaccine Safety Surveillance

New Safety Signals and Established Adverse Events

The Centers for Disease Control and Prevention (CDC) identified two new statistical safety signals during surveillance of the 2024-2025 COVID-19 vaccines: Guillain-Barré syndrome in adults ≥65 years and ischemic stroke in adults ≥50 years, though evidence remains inconclusive whether these represent actual risks 1
The CDC's Vaccine Safety Datalink (VSD) surveillance detected Guillain-Barré syndrome as a signal among persons aged ≥65 years during the 2023-2024 vaccine season, with current evidence being inconclusive as to whether this signal represents an actual risk 1
Ischemic stroke was detected among adults aged ≥50 years, with cumulative data to date not providing clear and consistent evidence of a safety problem for ischemic stroke 1
The American College of Cardiology and other guideline societies acknowledge that myocarditis and pericarditis remain the most well-established serious adverse events, particularly after mRNA vaccines, with a risk highest after the second dose in young males aged 12-29 years, at 39-47 cases per million vaccinated 3, 4
The certainty assessment for myocarditis/pericarditis remains low for adults and adolescents, and very low for children, according to the CDC 2

The Advisory Committee on Immunization Practices (ACIP) continues to recommend 2024-2025 COVID-19 vaccination for all persons aged ≥6 months, as the benefits of COVID-19 vaccination substantially outweigh any identified or theoretical risks 1, 2
Vaccination providers are required to report to VAERS vaccine administration errors, serious adverse events, cases of multisystem inflammatory syndrome, cases of myocarditis or pericarditis, and COVID-19 cases resulting in hospitalization or death after vaccination 3, 4
For chest pain occurring early after mRNA vaccination, evaluation should include ECG, cardiac troponin, and echocardiogram, and if myocarditis is suspected, cardiology consultation and cardiac MRI should be considered 5, 6
The CDC recommends maintaining heightened awareness for Guillain-Barré syndrome symptoms in adults ≥65 years and evaluating stroke symptoms promptly in adults ≥50 years, recognizing that COVID-19 infection itself carries stroke risk 1