FDA Halts Pediatric RSV Vaccine Trials Due to Safety Concerns
Clinical Hold:
The FDA has placed a hold on all clinical studies of RSV vaccines for infants due to safety concerns, following severe cases reported in a trial involving Moderna's mRNA-based vaccine candidates23.
Safety Signal:
A phase 1 trial evaluating two Moderna RSV vaccines (mRNA-1365 and mRNA-1345) found a higher incidence of severe lower respiratory tract infections in infants who received the vaccine compared to those who received a placebo. Five of six infants required hospitalization, with one needing mechanical ventilation2.
VAERD Risk:
The FDA is concerned about the potential for vaccine-associated enhanced respiratory disease (VAERD), a condition where vaccination may increase the severity of subsequent RSV infections15.
Future Development:
The FDA's Vaccine and Related Biological Products Advisory Committee (VRBPAC) is reviewing the safety data and discussing implications for the future development of RSV vaccines for infants23.
Risk Mitigation:
The FDA emphasizes the need for cautious approaches in pediatric RSV vaccine development, including rational vaccine design, nonclinical studies to ensure adequate immune responses, and clinical study guardrails to monitor safety and stop criteria5.
Adult and Pregnant Populations:
RSV vaccines have been approved for older adults and pregnant individuals, with ongoing safety monitoring to address potential risks such as Guillain-Barré syndrome and preterm births4.
Sources:
1. https://www.fda.gov/media/184380/download
2. https://www.beckershospitalreview.com/pharmacy/pediatric-rsv-vaccines-on-hold-fda.html
3. https://www.biopharmadive.com/news/fda-rsv-vaccine-infants-safety-panel-vrbpac/735464/