“…In the last 10 years, many researchers have been using mathematical model to study the dynamics of HBV transmission. For example, the authors (Adu, Aidoo, Darko, & Osei-Frimpong, 2014;Akbari, Kamyad, & Heydari, 2016;Aniji, Kavitha, & Balamuralitharan, 2019;2014;Khan & Zaman, 2016;Kimbir, Aboiyar, Abu, & Onah, 2014;Nana-Kyere, Ackora-Prah, Okyere, Marmah, & Afram, 2017;Nayeem & Podder, 2014;Seyoum Desta & Koya, 2019;Shaban & Manoza, 2016;Shi, Lu, & Wang, 2019;Wiah, Makinde, & Adetunde, 2015;Zhang, Guo, & Smith, 2018;Zou, Zhang, & Ruan, 2010) propose mathematical model of HBV transmission dynamics. However, most these works did not consider both the effect of memory using fractional order derivatives and age structure model simultaneously.…”