Bull Math Biol. 2026 Jul 4;88(7):134. doi: 10.1007/s11538-026-01690-8.
ABSTRACT
Vaccination programs have helped reduce case numbers and the death toll of COVID-19 significantly over the past few years. The spread and control of COVID-19 have been studied by means of ODE-based compartmental models in a number of studies. However, studies on the different benefits of vaccines, other than blocking infections, remain a paucity. In this study, we developed an ODE-based compartmental model with a separate disease progression path for vaccinated individuals. Key parameters were defined to account for the different facets of vaccine effectiveness: (1) blocking infections; (2) decreasing transmission; (3) expediting recovery; (4) reducing severe morbidity; and (5) preventing disease mortality. Sensitivity analyses and numerical simulations on the reproduction number, number of infections, reduction in peak infections, and cumulative disease-induced deaths provided important insights into the impact of different aspects of vaccine effectiveness on disease control. Specifically, vaccine benefits that reduce disease spread or accelerate recovery have a more substantial impact on the overall population (both vaccinated and unvaccinated individuals) than do vaccine benefits that reduce severe infections or death. The latter type of vaccines does not exhibit a considerable impact on the overall epidemic at the population level, but has a major impact only on the vaccinated individuals. In conclusion, infection burden can be reduced drastically with vaccines that have high potential in blocking infections, decreasing infectivity, and expediting recovery.
PMID:42400854 | DOI:10.1007/s11538-026-01690-8
