TY - JOUR T1 - Stability and Persistence of an Age Structured Epidemic Model with Mutation and Vaccination AU - Duan , Xi-Chao AU - Li , Xi-Na AU - Li , Xue-Zhi AU - Martcheva , Maia JO - CSIAM Transactions on Life Sciences VL - 3 SP - 438 EP - 465 PY - 2025 DA - 2025/10 SN - 1 DO - http://doi.org/10.4208/csiam-ls.SO-2024-0010 UR - https://global-sci.org/intro/article_detail/csiam-ls/24510.html KW - Age structured epidemic model, mutation, vaccination, basic reproduction number, local stability, uniform persistence. AB -

In this paper, we propose an age-structured epidemic model with strain mutation and age-based vaccination. We define the reproduction numbers of both the original and mutant strains ($R_{0}^{1}$ and $R_{0}^{2}$). If the reproduction number $R_{0} < 1$, the disease-free steady state is locally asymptotically stable. If the reproduction number $R_{0}^{2} > 1$, there exists a dominant steady state of the mutant strain. Conditions for local stability of this dominant steady state are also obtained. If both reproduction numbers $R_{0}^{1}$ and $R_{0}^{2}$ are greater than 1, a coexistence steady state may occur. Finally, the uniform persistence of the disease described by our age-structured model is strictly proved when the reproduction number $R_{0}^{1} > 1.$ By using the data of the COVID-19 epidemic in Wuhan and the theoretical results obtained in this paper, some numerical calculations are carried out to demonstrate the effect of the age-based vaccination strategy.