A recent study conducted by researchers using electronic health records from a large South Carolina health system indicates that the 2024-2025 mRNA COVID-19 vaccine offers moderate protection against hospitalization and emergency department visits related to the virus. The findings, published in the journal PubMed, assessed vaccine effectiveness between September 1, 2024, and April 16, 2025.
The study involved a matched sample of 30,080 individuals, with 10,029 receiving the updated mRNA vaccine. Researchers found the vaccine to be 41.3% effective (95% Confidence Interval: 17.2-58.4) in preventing emergency department visits or more severe care, and 46.1% effective (95% Confidence Interval: 13.6-66.3) against hospitalization. These results suggest a continued, though lessened, benefit from vaccination even in populations with significant prior exposure to the virus through infection and previous vaccination campaigns.
The Food and Drug Administration (FDA) approved and authorized the updated mRNA COVID-19 vaccines for emergency use in 2024, designed to target currently circulating variants. According to the FDA, the updated formula aims to better protect against COVID-19. The Centers for Disease Control and Prevention (CDC) recommends mRNA vaccines from Moderna and Pfizer-BioNTech, alongside a protein subunit vaccine from Novavax, for use in the United States.
The CDC’s guidance, updated for the 2025-2026 vaccination schedules, emphasizes individual-based decision-making, as well known as shared clinical decision-making, regarding vaccination. Currently, Moderna offers Spikevax for those aged 6 months and older, and mNexspike for those 12 years and older. Pfizer-BioNTech’s Comirnaty is approved for ages 5 years and older, though there is no currently authorized vaccine for children aged 6 months to 4 years. Novavax’s Nuvaxovid is approved for individuals 12 years and older.
The South Carolina study highlights the need for sustained public health efforts to increase vaccination coverage, particularly among older adults and individuals with medical comorbidities, given the low uptake observed in the studied population. Researchers noted the ongoing challenges posed by emerging variants. A separate study, published in JAMA Network Open, estimates vaccine effectiveness against severe COVID-19 and investigates potential variations based on SARS-CoV-2 lineage and spike protein mutations.
