RSVpreF Vaccine Shows Strong Safety Profile in Adults, Global Analysis Finds

Key Clinical Summary

• Pooled data from 8 clinical trials (n = 46 913) confirmed a favorable safety profile for the bivalent respiratory syncytial virus prefusion F (RSVpreF) vaccine in adults.
• Local and systemic reactions were mild to moderate; injection-site pain was most common (18.9% vs 7.4% with placebo).
• Post-marketing surveillance confirmed no new safety concerns, including no cases of Guillain-Barré syndrome or atrial fibrillation.

A large integrated analysis published in Vaccines by Pfizer researchers evaluated the safety of the bivalent RSVpreF vaccine across 8 adult clinical trials and post-marketing data. Findings confirm that RSVpreF demonstrates a consistent, favorable safety profile among immunocompetent adults aged 18 years and older, including pregnant participants.

Study Findings

The pooled analysis encompassed 46 913 adults who received either RSVpreF or placebo in 8 trials. Among non-pregnant adults ≥18 years (n = 9517), local and systemic reactions occurred more often with RSVpreF, though events were typically mild and transient. Injection-site pain was the most frequently reported local reaction (18.9% vs 7.4% placebo). Fatigue (23.5% vs 18.4%) and headache (19.5% vs 15.0%) were the most common systemic events.

Rates of adverse events (AEs) within 1 month of vaccination were comparable between vaccine and placebo groups (12.8% vs 13.1%), and severe AEs were rare (≤1.5%). Differences in vaccine-related AEs between RSVpreF and placebo were minimal (<0.2% across all categories). Serious AEs occurred in ≤14% of participants overall (12.6% RSVpreF; 14.0% placebo).

Importantly, no cases of atrial fibrillation, Guillain-Barré syndrome, or acute polyneuropathy were observed. Post-marketing surveillance in non-pregnant adults confirmed these findings and revealed no new safety signals, reinforcing consistency across clinical and real-world data.

Clinical Implications

These results support RSVpreF as a well-tolerated option for preventing RSV infection in adults, including those without underlying health risks. Although severe RSV disease is more common in immunocompromised or older populations, the analysis highlights the unmet need for protection among younger, immunocompetent adults, where treatment remains largely supportive.

Because natural RSV infection does not induce durable immunity, vaccination strategies such as RSVpreF could fill a persistent prevention gap. For pharmacists and clinicians, these findings provide reassurance regarding vaccine safety during clinical rollout and pharmacovigilance monitoring.

Conclusion

The integrated global analysis and post-marketing review confirm that the bivalent RSVpreF vaccine maintains an acceptable and consistent safety profile in adult populations. Continued real-world monitoring will help sustain confidence in RSV prevention and inform clinical best practices for adult immunization.

Reference

Llangovan K, Radley D, Patton M, et al. Integrated analysis of the safety experience in adults with the bivalent respiratory syncytial virus prefusion F vaccine. Vaccines (Basel). 2025;13(8):827. doi:10.3390/vaccines13080827