The potential clinical impact and cost-effectiveness of the updated COVID-19 mRNA Fall 2023 vaccines in the United States

Objectives To assess the potential clinical impact and cost-effectiveness of COVID-19 mRNA vaccines updated for Fall 2023 in adults ≥18 years over a 1-year analytic time horizon (September 2023-August 2024). Methods A compartmental Susceptible-Exposed-Infected-Recovered model was updated to reflect COVID-19 in summer 2023. Numbers of symptomatic infections, COVID-19 related hospitalizations and deaths, and costs and quality-adjusted life-years (QALYs) gained were calculated using a decision tree model. The incremental cost-effectiveness ratio (ICER) of a Moderna updated mRNA Fall 2023 vaccine (Moderna Fall Campaign) was compared to no additional vaccination. Potential differences between the Moderna and the Pfizer-BioNTech Fall 2023 vaccines were examined. Results Base case results suggest the Moderna Fall Campaign would decrease the expected 64.2 million symptomatic infections by 7.2 million (11%) to 57.0 million. COVID-19-related hospitalizations and deaths are expected to decline by 343,000 (–29%) and 50,500 (–33%), respectively. The Moderna Fall Campaign would increase QALYs by 740,880 and healthcare costs by $5.7 billion relative to No Vaccine, yielding an ICER of $7,700 per QALY gained. Using a societal cost perspective, the ICER is $2,100. Sensitivity analyses suggest that vaccine effectiveness, COVID-19 incidence, hospitalization rates and costs drive cost-effectiveness. With a relative vaccine effectiveness (rVE) of Moderna versus Pfizer-BioNTech of 5.1% for infection and 9.8% for hospitalization, use of the Moderna vaccine is expected to prevent 24,000 more hospitalizations and 3,300 more deaths than the Pfizer-BioNTech vaccine. Limitations and Conclusions As COVID-19 becomes endemic, future incidence, including patterns of infection, are highly uncertain. Vaccine effectiveness of Fall 2023 vaccines is unknown, and it is unclear when a new variant that evades natural or vaccine immunity will emerge. Despite these limitations, the Moderna Fall 2023 vaccine can be considered cost-effective relative to no vaccine.