Modeling the potential public health and economic impact of different COVID-19 booster dose vaccination strategies with an adapted vaccine in the United Kingdom.

Background: Updating vaccines is essential for combatting emerging coronavirus disease 2019 (COVID-19) variants. This study assessed the public health and economic impact of a booster dose of an adapted vaccine in the United Kingdom (UK).

Methods: A Markov-decision tree model estimated the outcomes of vaccination strategies targeting various age and risk groups in the UK. Age-specific data derived from published sources were used. The model estimated case numbers, deaths, hospitalizations, medical costs, and societal costs. Scenario analyses were conducted to explore uncertainty.

Results: Vaccination targeting individuals aged ≥ 65 years and the high-risk population aged 12-64 years was estimated to avert 701,549 symptomatic cases, 5,599 deaths, 18,086 hospitalizations, 56,326 post-COVID condition cases, and 38,263 lost quality-adjusted life years (QALYs), translating into direct and societal cost savings of £112,174,054 and £542,758,682, respectively. The estimated economically justifiable price at willingness-to-pay thresholds of £20,000 and £30,000 per QALY was £43 and £61, respectively, from the payer perspective and £64 and £82, respectively, from the societal perspective. Expanding to additional age groups improved the public health impact.

Conclusions: Targeting individuals aged ≥ 65 years and those aged 12-64 years at high risk yields public health gains, but expansion to additional age groups provides additional gains.