Authors: Plaire Tchinda Mouofo ¹; Jean Jules Tewa ²; Boulchard Mewoli ¹; Bowong Samuel ³

• 1 Département de Mathématiques Université de Yaoundé 1 = Department of Mathematics [Yaoundé, Cameroon]
• 2 National Advanced School of Engineering
• 3 Unité de modélisation mathématique et informatique des systèmes complexes [Bondy]

It has been proven that vaccine can play an important role for eradication of hepatitis B infection. When the mutant strain of virus appears, it changes all treatments strategies. The current problem is to find the critical vaccine threshold which can stimulate the immune system for eradicate the virus, or to find conditions at which mutant strain of the virus can persist in the presence of a CTL vaccine. In this paper, the dynamical behavior of a new hepatitis B virus model with two strains of virus and CTL immune responses is studied. We compute the basic reproductive ratio of the model and show that the dynamic depend of this threshold. After that, we extend the model incorporating pulse vaccination and we find conditions for eradication of the disease. Our result indicates that if the vaccine is sufficiently strong, both strains are driven to extinction, assuming perfect adherence.