![\"RSV](\"https:\/\/www.tomgrimshaw.com\/tomsblog\/wp-content\/uploads\/2025\/09\/RSV_Vaccine_Adverse_Events.jpg\")
<\/p>\n<\/p>\n
By Nicolas Hulscher, MPH<\/a><\/strong><\/p>\n A new peer-reviewed pharmacovigilance study<\/a><\/strong> just published in Human Vaccines & Immunotherapeutics<\/em> analyzed nearly 18,000 adverse event reports<\/strong> tied to the three FDA-approved RSV vaccines \u2014 Pfizer\u2019s Abrysvo<\/em>, GSK\u2019s Arexvy<\/em>, and Moderna\u2019s mRESVIA<\/em>.<\/p>\n The findings are alarming: Pfizer\u2019s vaccine generated 103 positive safety signals<\/strong>, including fetal death, hemorrhage in pregnancy, and preterm birth, while GSK\u2019s vaccine generated 91 signals<\/strong>, including paralysis, Guillain-Barr\u00e9 syndrome, and mini-strokes. Both carried strong signals for immune destruction (thrombocytopenia) and serious neurological damage \u2014 in some cases appearing over 200\u00d7 more likely compared to other vaccines.<\/p>\n 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<\/strong>.<\/p>\n And while both Pfizer\u2019s and GSK\u2019s vaccines generated thousands of signals, Moderna\u2019s mRNA RSV shot had too few reports (just 35 cases) to allow for meaningful analysis. That doesn\u2019t mean it\u2019s safe \u2014 only that there isn\u2019t enough post-market data yet to detect patterns.<\/p>\n