Estimating the potential public health and economic impact of vaccination timing: A modeling study of COVID-19 vaccination in the United Kingdom

This study evaluated the public health and economic impact of timely protection against COVID-19 infection with an adapted vaccine in the United Kingdom. A static decision-tree model was used to estimate the impact of timely protection with an autumn dose and a spring dose and assess how delays in the start of the vaccination program affect the impact. The model examined a hypothetical year based on the average age-stratified incidence and severity reported in public health surveillance data for the 2022/2023 and the 2023/2024 seasons. Other age-stratified parameters vaccine coverage, cost, and vaccine effectiveness parameters were informed by literature. Timely protection with the autumn dose for those aged ≥75 y and the high-risk population aged 18-74 was estimated to avert 1.0 million cases, 15,642 hospitalization, 3,897 deaths, 82,977 post-COVID condition cases, £179 million in direct medical costs, and £195 million in productivity losses. Timely protection with the spring dose for those aged ≥75 y and the high-risk population aged 18-74 was estimated to avert 98,446 cases, 1,477 hospitalization, 279 deaths, 8,357 post-COVID condition cases, £6 million in direct medical costs, and £14 million in productivity losses. Delays in the start of the vaccination program substantially reduced the estimated public health and economic impact of vaccination for both the autumn and spring doses. Adapted vaccines for COVID-19 remain an important public health tool for reducing the health and economic burden. However, delays in the start of vaccination campaigns may erode the potential impact.