Background: Despite the advent of safe and effective coronavirus disease 2019 vaccines, pervasive inequities in global vaccination persist.Methods: We projected health benefits and donor costs of delivering vaccines for up to 60% of the population in 91 low- and middle-income countries (LMICs). We modeled a highly contagious (Re at model start, 1.7), low-virulence (infection fatality ratio [IFR], 0.32%) "Omicron-like" variant and a similarly contagious "severe" variant (IFR, 0.59%) over 360 days, accounting for country-specific age structure and healthcare capacity. Costs included vaccination startup (US$630 million) and per-person procurement and delivery (US$12.46/person vaccinated).Results: In the Omicron-like scenario, increasing current vaccination coverage to achieve at least 15% in each of the 91 LMICs would prevent 11 million new infections and 120 000 deaths, at a cost of US$0.95 billion, for an incremental cost-effectiveness ratio (ICER) of US$670/year of life saved (YLS). Increases in vaccination coverage to 60% would additionally prevent up to 68 million infections and 160 000 deaths, with ICERs Conclusions: Funding expanded COVID-19 vaccine delivery in LMICs would save hundreds of thousands of lives, be similarly or more cost-effective than other donor-funded global aid programs, and improve health equity. [ABSTRACT FROM AUTHOR]