Moderna’s 2024–2025 COVID-19 Vaccine: Composition Updates and Interim Effectiveness Data

Moderna’s 2024–2025 COVID-19 Vaccine: Composition Updates and Interim Effectiveness Data

The 2024–2025 formulation of Moderna’s SPIKEVAX® (COVID-19 Vaccine, mRNA) reflects both an antigenic shift and operational refinements. This monovalent vaccine was developed based on the Omicron variant KP.2, a member of the JN.1 lineage. The update aligns with recommendations from the CDC’s Advisory Committee on Immunization Practices (ACIP) and is expected to offer protection against related strains, including KP.3.1.1, XEC, and MC.1.

The 2024-2025 SPIKEVAX vaccine received full FDA approval for individuals aged 12 years and older. For children aged 6 months through 11 years, it remains available under Emergency Use Authorization. The FDA has indicated that COVID-19 vaccines will continue to undergo annual review—similar to the model that’s used for seasonal influenza vaccines.

What to Know About the Packaging Updates

As of January 2025, SPIKEVAX became available in two newly authorized packaging configurations:

• A carton containing two individual single-dose pre-filled syringes
• A blister pack of two syringes

To support these changes, the package insert includes updated thawing time instructions. These adjustments are intended to enhance flexibility across clinical and pharmacy workflows.

A Review of the Interim Effectiveness Data

On February 27, 2025, the CDC published interim vaccine effectiveness (VE) estimates for the 2024–2025 COVID-19 season in Morbidity and Mortality Weekly Report (MMWR), based on data from the VISION and IVY networks collected between September 2024 and January 2025. The VISION Network is an electronic health records–based platform that includes outpatient and inpatient encounters across multiple states, while the IVY Network conducts prospective, hospital-based surveillance for COVID-19–like illness in adults admitted to participating medical centers.

The report included data on multiple COVID-19 vaccines, including the updated SPIKEVAX formulation. Key findings from the MMWR report included:

• During this period, the predominant circulating SARS-CoV-2 lineages were KP.3 (52 percent), KP.2 (15 percent), and XEC (14 percent).
• 33 percent VE against COVID-19–associated emergency department (ED) or urgent care (UC) visits among adults aged ≥18 years who received a 2024–2025 COVID-19 vaccine dose compared to those who had not.
• Among immunocompetent adults aged ≥65 years, VE against COVID-19–associated hospitalization was 45-46 percent for those who received a 2024–2025 COVID-19 vaccine dose compared to those who had not.
• For immunocompromised adults aged ≥65 years, VE against hospitalization was 40 percent.

These findings indicate that the 2024–2025 formulation offers additional protection against COVID-19–related ED/UC visits and hospitalizations. They support ACIP’s recommendation that all individuals aged ≥6 months receive an updated vaccine dose for the season. The data also support continued vaccination in individuals with prior infection or previous COVID-19 vaccinations, as the estimates reflect added benefit beyond existing immunity.

With its antigenic update and expanded packaging formats, the 2024–2025 SPIKEVAX formulation remains a key component of the national COVID-19 prevention strategy. However, the reported emergence of new lineages, such as LP.8.1, further underscore the importance of ongoing genomic surveillance and the potential need for future vaccine reformulations to sustain protection.

References

1. About COVID-19. Centers for Disease Control. Updated June 13, 2024. Accessed April 8, 2025. https://www.cdc.gov/covid/about/index.html
2. Link-Gelles R, Chickery S, Webber A, et al. Interim Estimates of 2024-2025 COVID-19 Vaccine Effectiveness Among Adults Aged ≥18 Years - VISION and IVY Networks, September 2024-January 2025. MMWR Morb Mortal Wkly Rep. 2025;74(6):73-82. Published February 27, 2025.
3. Spikevax. Prescribing information. ModernaTX, Inc; 2024.
4. U.S. Food and Drug Administration. FDA approves and authorizes updated mRNA COVID-19 vaccines to better protect against currently circulating variants. August 22, 2024. Accessed April 10, 2025. https://www.fda.gov/news-events/press-announcements/fda-approves-and-authorizes-updated-mrna-covid-19-vaccines-better-protect-against-currently
5. U.S. Food and Drug Administration. SPIKEVAX Supplement Approval. January 25, 2025. Accessed April 8, 2025. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.fda.gov/media/185305/download?attachment