The Effectiveness and Influence of COVID-19 Vaccination on Perinatal Individuals and Their Newborns: An Updated Meta-Analysis.

The COVID-19 pandemic has disproportionately affected pregnant individuals, increasing risks of severe illness and adverse outcomes. While vaccination is a key mitigation strategy, initial exclusion from clinical trials led to limited safety data. Despite evidence of vaccine effectiveness, hesitancy persists in this population. This meta-analysis aims to evaluate the efficacy and impact of COVID-19 vaccination in pregnant individuals, synthesizing evidence from 82 studies (3,676,654 participants) retrieved from PubMed, Embase, Cochrane Library, and Scopus (2019-2024). Study quality was assessed using the Newcastle-Ottawa scale (80/82 scored ≥ 7). Vaccination reduced maternal SARS-CoV-2 infection risk by 48% (odds ratio [OR] = 0.52), with mRNA vaccines showing higher efficacy (52% vs. 43% for inactivated). Maternal hospitalization risk decreased by 42% (OR = 0.58), and severe outcomes by 50% (OR = 0.50). Furthermore, neonatal outcomes improved, including reduced infection (OR = 0.69), preterm birth (OR = 0.87), stillbirth (OR = 0.64), and neonatal death (OR = 0.47). Protection against neonatal death was stronger in individuals without prior infection (OR = 0.43). Third-trimester vaccination may offer better protection against preterm birth. Overall, COVID-19 vaccination during pregnancy effectively mitigates infection and adverse maternal/neonatal outcomes, supporting its clinical recommendation.