Study: No link between COVID-19 vaccines and autism

A study of 434 children presented at the Society for Maternal‑Fetal Medicine meeting found no differences on four autism screening tools between toddlers born to mothers who received COVID‑19 mRNA vaccines before or during pregnancy and those born to unvaccinated mothers.

A new study reports no increase in early autism screening signs among toddlers born to mothers who received COVID‑19 mRNA vaccines before or during pregnancy. Researchers presented the results at the Society for Maternal‑Fetal Medicine 2026 Pregnancy Meeting, and the paper is scheduled for publication in the journal Pregnancy in February 2026. The study followed 434 children born at 14 medical centers between May 2024 and March 2025 and compared screening scores for children of vaccinated and unvaccinated mothers. Authors and outside experts described the results as reassuring while noting limits to the study. Key points: - The study included 434 children, approximately half born to mothers who received at least one dose of an mRNA COVID‑19 vaccine during pregnancy or within 30 days before pregnancy, and half to unvaccinated mothers. - Toddlers aged 18 to 30 months were assessed with four standard screening tools: the Ages and Stages Questionnaire Version 3 (ASQ‑3), the Child Behavior Checklist, the Modified Checklist for Autism in Toddlers, and the Early Childhood Behavior Questionnaire. - Researchers found no significant differences between the vaccinated and unvaccinated groups on any of the four screening assessments. - Alycia Halladay, PhD, and the study authors described the findings as reassuring; Halladay characterized the results as clear and convincing for most children. - Limitations noted include follow-up only to about 2½ years of age and that screening tools are not definitive diagnostic tests, so some diagnoses made later could be missed. - The study was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and will appear in the journal Pregnancy. Summary: The study adds to research reporting no early increase in autism screening signals after maternal COVID‑19 vaccination during or shortly before pregnancy. Experts emphasized the value of the findings while also noting the need for longer follow‑up and additional studies to track diagnoses as children get older.