Abstract
The emergence of mutations in the virus, both naturally occurring and as a result of therapy, poses a challenge to the effectiveness of these mutations. A mathematical model is developed to investigate the impact of mutations on the transmission dynamics of HBV. The model takes into account that an individual can be infected with either the wild-type virus, mutant virus, or both. In addition, it also considers that an individual infected with both the wild-type and the mutant viruses can transmit either the wild-type, the mutant, or both viruses. By using the Next Generation Matrix, the model exhibits three partial basic reproduction numbers which correspond to individuals infected with only the wild-type strain, only the mutant strain, or both strains. The full epidemiological model has a basic reproduction number (R0) equal to the maximum value of these three partial reproduction numbers. The analysis shows that when R0 is less than 1, the Disease Free Equilibrium is globally asymptotically stable, while it is unstable when R0 is greater than 1. The study also identifies various boundary equilibria and shows that the endemic equilibrium exists. The results provide insights into the role of mutations in HBV transmission and can inform strategies for controlling the spread of the virus. We also carried out a sensitivity analysis of the model and found that parameters related to prenatally infected individuals significantly influence model outcomes. More precisely, we found that vertical transmission is one of the main routes of HBV transmission. In addition, we obtain that high values of the infectivity rates of chronic individuals are associated with an increase in acute infections. Hence, neonatal vaccination, awareness campaigns, and HBV tests to detect HBV carriers are greatly recommended. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.