04: Active Safety Surveillance of the 2023–2024 COVID-19 Vaccine Formulation: Findings from VSD

Music City Center 

Real-world post-vaccine safety monitoring is crucial for detecting adverse events and maintaining public trust. This study applied Rapid Cycle Analysis (RCA) to assess 2023–2024 COVID-19 vaccines (Pfizer, Moderna, Novavax) for 14 outcomes, including ischemic stroke, GBS, and myocarditis.
VSD data from nine healthcare organizations included 2.7M doses (Sep 2023–Apr 2024). Outcomes were identified in healthcare records. RCA used a concurrent comparator design to compare adverse event rates across risk and comparison intervals. Weekly monitoring with Pocock alpha-spending controlled Type I error ensured real-time safety assessment and reduced bias.
RCA identified a GBS signal after Pfizer in ≥65 yrs (aRR: 4.45, 95% CI: 1.07–22.62) and ischemic stroke signals with Pfizer (18–64 yrs: aRR: 1.48, 95% CI: 1.04–2.11) and Moderna (≥65 yrs: aRR: 1.68, 95% CI: 1.05–2.70). No signals were found for other outcomes.
RCA enables real-time vaccine safety monitoring, addressing limits of traditional comparators. While GBS and stroke signals require further evaluation, the 2023–2024 COVID-19 vaccines show a reassuring safety profile. Ongoing monitoring remains key for public trust and safety.

Vaccine Safety
Post-Vaccination Surveillance
Adverse Events
Rare Events
Signal Detection

Rapid Cycle Analysis (RCA)
Sequential Analysis
Concurrent Comparator Design
Pocock Alpha-Spending
Real-Time Monitoring

Vaccine Safety Datalink (VSD)
ICD-10 Codes
Healthcare Records

Guillain-Barré Syndrome (GBS)
Ischemic Stroke, Myocarditis
Adjusted Rate Ratio (aRR)
Risk and Comparison Intervals

COVID-19 Vaccine
Pfizer
Moderna
Novavax 

Government Statistics Section