RSV Shots Linked to Over 200 Safety Signals — Serious Neurological, Cardiac, and Pregnancy Harms Identified

RSV Vaccine Adverse Events

By Nicolas Hulscher, MPH

A new peer-reviewed pharmacovigilance study just published in Human Vaccines & Immunotherapeutics analyzed nearly 18,000 adverse event reports tied to the three FDA-approved RSV vaccines — Pfizer’s Abrysvo, GSK’s Arexvy, and Moderna’s mRESVIA.

The findings are alarming: Pfizer’s vaccine generated 103 positive safety signals, including fetal death, hemorrhage in pregnancy, and preterm birth, while GSK’s vaccine generated 91 signals, including paralysis, Guillain-Barré syndrome, and mini-strokes. Both carried strong signals for immune destruction (thrombocytopenia) and serious neurological damage — in some cases appearing over 200× more likely compared to other vaccines.

Researchers used standard pharmacovigilance methods (Reporting Odds Ratios and Bayesian algorithms) to compare how often certain events were reported after RSV vaccination versus all other vaccines in the system.

And while both Pfizer’s and GSK’s vaccines generated thousands of signals, Moderna’s mRNA RSV shot had too few reports (just 35 cases) to allow for meaningful analysis. That doesn’t mean it’s safe — only that there isn’t enough post-market data yet to detect patterns.

https://open.substack.com/pub/petermcculloughmd/p/breaking-rsv-shots-linked-to-over