Clinical and Economic Perspectives on Influenza and COVID-19 Vaccine Combinations
Author(s)
José BARTELT-HOFER, PhD, Maribel Tribaldos Causadias de Su, MSc, PhD, MD.
HE&OR, Sanofi, Lyon, France.
HE&OR, Sanofi, Lyon, France.
OBJECTIVES: Influenza and COVID-19 impose a significant burden for older adults in the United States (US), yet COVID-19 vaccination rates lag significantly behind those for influenza, and only one-third receive both vaccines simultaneously. Combination influenza-COVID-19 vaccines, currently in phase II/III trials, may reduce administration burden and increase vaccine coverage rates (VCR). This study evaluates the public health and economic impact of current standalone vaccination versus mRNA and recombinant combination vaccines in older adults aged over 65 years, from a US healthcare payor perspective.
METHODS: We modeled health and economic impact following standalone or combination vaccinations in a one-year time horizon. The model incorporated recent US, age-specific demographics, disease patterns, VCR, and 2024 healthcare costs, excluding vaccine acquisition. Among alternatives, vaccine efficacy (VE) against COVID-19 was set equal, and considered a relative VE of 15.3% for recombinant influenza vaccine against standard dose. Outcomes assume combined vaccines to even out VCR at 51.1% for both diseases. Post-vaccination adverse events (AEs), grade 1 or 2, and 3 were classified according to their healthcare-seeking behaviour as non-medically attended, or outpatient, respectively.
RESULTS: At a 51.1% VCR, 30.31 million out of 59.31 million US older adults were assumed to receive an influenza and COVID-19 vaccination combination. Compared to combination vaccines, standalone vaccinations increased hospitalizations by 8.9% and general practitioner visits by 6.2%, which translated into $16.2 million in additional costs. The recombinant combination vaccine yielded 17.66 million fewer AEs (15.01 million grade 1 & 2; 2.65 million grade 3 AEs) compared to the mRNA combination vaccine, which equated to $17.43 million grade 3 mRNA-related reactogenicity costs.
CONCLUSIONS: The recombinant vaccine combination demonstrated notable clinical and economic outcomes, benefiting from its enhanced influenza component and established safety profile. Moreover, by addressing the VCR disparity between influenza and COVID-19, combination vaccines offer substantial clinical and economic advantages over standalone vaccinations.
METHODS: We modeled health and economic impact following standalone or combination vaccinations in a one-year time horizon. The model incorporated recent US, age-specific demographics, disease patterns, VCR, and 2024 healthcare costs, excluding vaccine acquisition. Among alternatives, vaccine efficacy (VE) against COVID-19 was set equal, and considered a relative VE of 15.3% for recombinant influenza vaccine against standard dose. Outcomes assume combined vaccines to even out VCR at 51.1% for both diseases. Post-vaccination adverse events (AEs), grade 1 or 2, and 3 were classified according to their healthcare-seeking behaviour as non-medically attended, or outpatient, respectively.
RESULTS: At a 51.1% VCR, 30.31 million out of 59.31 million US older adults were assumed to receive an influenza and COVID-19 vaccination combination. Compared to combination vaccines, standalone vaccinations increased hospitalizations by 8.9% and general practitioner visits by 6.2%, which translated into $16.2 million in additional costs. The recombinant combination vaccine yielded 17.66 million fewer AEs (15.01 million grade 1 & 2; 2.65 million grade 3 AEs) compared to the mRNA combination vaccine, which equated to $17.43 million grade 3 mRNA-related reactogenicity costs.
CONCLUSIONS: The recombinant vaccine combination demonstrated notable clinical and economic outcomes, benefiting from its enhanced influenza component and established safety profile. Moreover, by addressing the VCR disparity between influenza and COVID-19, combination vaccines offer substantial clinical and economic advantages over standalone vaccinations.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
EE132
Topic
Clinical Outcomes, Economic Evaluation, Health Technology Assessment
Disease
Vaccines