# Real-World Evidence Evaluation of Respiratory Syncytial Virus (RSV) Vaccines: Deep Dive into Vaccine Adverse Events Reporting System

## TL;DR

This study evaluates the real-world safety of RSV vaccines using VAERS data from 2023 to 2025, finding mostly mild side effects but some concerning trends.

## Contribution

The study provides the first real-world evidence analysis of RSV vaccines using VAERS data, highlighting safety trends and errors.

## Key findings

- Most adverse events were mild, such as injection site pain and fatigue.
- Hospitalization rates increased from 4.8% in 2023 to 7.5% in 2025.
- Vaccination errors, like administering during pregnancy, were observed.

## Abstract

Background: Respiratory Syncytial Virus is a predominant source of morbidity and mortality, particularly among babies, the elderly, and immunocompromised patients. Recent developments in RSV vaccines, approved by the FDA for high-risk groups, have highlighted the necessity for post-marketing surveillance to evaluate their real-world safety and efficacy. Method: This study utilized data from the Vaccine Adverse Event Reporting System (VAERS) covering RSV vaccine administration between 2023 and May 2025. The VAERS database reported data on vaccine types, including Arexvy®, Abrysvo®, and mRESVIA® was analyzed for adverse events and vaccination errors. The demographic information, vaccination trends, and hospitalizations post-vaccination among the vaccinated individuals were accessed. Results: The analysis revealed that the most common adverse events were mild, such as injection site pain, erythema, fatigue, and extremity pain. The data also showed a gradual increase in hospitalization rates from 4.8% in 2023 to 7.5% in 2025. Vaccination errors, including inappropriate administration during pregnancy and excess doses, were also observed. A notable trend was the growing proportion of patients who experienced no adverse events, with the highest rate of symptom-free reports seen in 2025 (25.9%). Conclusions: RSV vaccines demonstrate a generally acceptable safety profile based on post-marketing surveillance data. However, the observed increase in hospitalization rates, vaccination errors, and pregnancy-related outcomes warrants continued active surveillance and cautious interpretation.