Background: With shifting epidemiology and changes in the vaccine funding landscape, resource use considerations for ongoing COVID-19 vaccination programs are increasingly important. We assessed the cost-effectiveness of COVID-19 vaccination programs, where eligibility is defined by combinations of age and chronic medical conditions, including a strategy similar to current Canadian recommendations, from the health system and societal perspectives. Methods: We used a static, individual-based probabilistic model simulating medically attended COVID-19 in a population of 1 million people followed over a 15-month time period to estimate costs in 2023 Canadian dollars, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs), discounted at 1.5%. COVID-19 epidemiology, vaccine characteristics, and costs were based on the most recently available data. Results: Annual vaccination for adults aged 65 years and older consistently emerged as a cost-effective intervention, with ICERs less than $50,000 per QALY compared to no vaccination for a range of model assumptions. Adding a second dose for adults aged 65 years and older or expanding programs to include vaccination for younger age groups, including those at higher risk of COVID-19 due to chronic medical conditions, generally resulted in ICERs of greater than $50,000 per QALY. Shifting timing of vaccination programs to better align with periods of high COVID-19 case occurrence could result in biannual vaccination for those aged 65 and older being a cost-effective strategy. Conclusions: COVID-19 vaccination programs may be cost-effective when focused on groups at higher risk of disease. Optimal timing of vaccination could improve the cost-effectiveness of various strategies.

The authors have declared no competing interest.

This research was supported, in part, by a Canada Research Chair in Economics of Infectious Diseases held by Beate Sander (CRC-2022-00362).

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