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Evaluating the Effectiveness of mRNA-1273.815 Against COVID-19 Hospitalization Among Adults Aged ≥ 18 Years in the
Amanda Wilson1, Neloufar Rahai2, Ekkehard Beck3
1Moderna, Inc., 325 Binney St., Cambridge, MA, 02142, USA. Amanda.Wilson@modernatx.com.
Introduction:
In September 2023 the Food and Drug Administration (FDA) approved an updated mRNA COVID-19 vaccine targeting the XBB.1.5 sublineage. This study evaluates the effectiveness of mRNA-1273.815, a 2023-2024 Omicron XBB.1.5-containing mRNA COVID-19 vaccine in preventing COVID-19-related hospitalizations and medically attended COVID-19 in US adults aged ≥ 18 years.
Methods:
This observational, matched cohort study used medical and pharmacy claims data from HealthVerity. Adults vaccinated with mRNA-1273.815 between September 12, 2023, and December 31, 2023, were followed through January 26, 2024. Vaccinated individuals were matched with individuals unvaccinated with any 2023-2024 COVID-19 vaccine on demographic and clinical characteristics. The primary and secondary outcomes were COVID-19 hospitalization and medically attended COVID-19, respectively. Inverse probability of treatment weighting and Cox proportional hazards regression were utilized to estimate vaccine effectiveness (VE).
Results:
The study included 1,272,161 vaccinated individuals matched 1:1 with unvaccinated individuals, with a maximum follow-up of 128 (median 84) days. The VE against COVID-19 hospitalization was 51% (95% confidence interval [CI]: 48-54%). Subgroup analyses showed a VE of 56% (95% CI 51-61%) among adults ≥ 65 years and 46% (95% CI 39-52%) in immunocompromised adults. For medically attended COVID-19, the VE was 25% (95% CI 24-27%). Time-varying analyses showed that while VE declined over time, VE remained significant.
Conclusion:
During the 2023-2024 respiratory season, the mRNA-1273.815 vaccine significantly protected against COVID-19-related hospitalizations and medically attended COVID-19 across diverse adult populations and demonstrated durability of the effect. These results support the continued use of updated COVID-19 vaccines to mitigate severe outcomes and maintain public health safety.
Insights
The updated mRNA-1273.815 COVID-19 vaccine showed 51% effectiveness against hospitalization and 25% against medically attended illness in US adults. This vaccine provides significant protection for diverse populations during the 2023-2024 season.
Area of Science:
- * Vaccinology and Virology
- * Public Health and Epidemiology
- * Infectious Disease Prevention
Background:
- * The US FDA approved an updated mRNA COVID-19 vaccine (mRNA-1273.815) in September 2023, targeting the Omicron XBB.1.5 sublineage.
- * This vaccine is designed for the 2023-2024 respiratory season to address circulating SARS-CoV-2 variants.
Purpose of the Study:
- * To evaluate the real-world effectiveness of the mRNA-1273.815 vaccine.
- * To assess its efficacy in preventing COVID-19-related hospitalizations and medically attended COVID-19.
- * To analyze vaccine effectiveness in various adult subgroups, including older adults and immunocompromised individuals.
Main Methods:
- * An observational, matched cohort study utilizing medical and pharmacy claims data.
- * Matching of vaccinated (mRNA-1273.815) and unvaccinated individuals based on demographic and clinical factors.
- * Application of inverse probability of treatment weighting and Cox proportional hazards regression to estimate vaccine effectiveness (VE).
Main Results:
- * Vaccine effectiveness against COVID-19 hospitalization was 51% (95% CI: 48-54%).
- * Effectiveness was higher in adults aged 65 years (56%) and in immunocompromised adults (46%).
- * VE against medically attended COVID-19 was 25% (95% CI: 24-27%), with significant protection observed over time.
Conclusions:
- * The mRNA-1273.815 vaccine provided significant protection against severe COVID-19 outcomes during the 2023-2024 season.
- * The vaccine demonstrated durability of effect across diverse adult populations.
- * Results support the ongoing use of updated COVID-19 vaccines for public health protection.
