Tehran University of Medical Sciences Journal of Medical Bacteriology 2251-8649 13 3 2025 08 24 131 145 Mahdi Bozorgi Kashan University of Medical Sciences. Pedram Pouyan Department of Biotechnology, Faculty of Life Science and Biotechnology, Islamic Azad University of Parand, Tehran, Iran. Ali Mashkani Department of Nursing, Sabzevar Branch, Islamic Azad University, Sabzevar, Iran. Mahdi Maloomi Isfahan University of Medical Science. Fatemeh Gozarnoie Kashan University of Medical Sciences. Somaieh Nasereslami Department of virology , Faculty of Medicine , Tarbiat Modares University, Tehran , Iran. Zeinab , Mohammadi Department of Microbiology and Virology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. Javad Fathi Department of Bacteriology and Virology, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran. Yalda Malekzadegan Department of Microbiology and Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran. Amir Jouya Talaei Halal Research Center of IRI, Food and Drug Administration, Ministry of Health and Medical Education, Tehran, Iran. Saina Najafi Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Mehrshad Fekri Department of Biochemistry, Faculty of Biological Sciences, North Tehran Branch, Islamic Azad University, Tehran, Iran. 2025 01 21 2025 02 06 Background:   Understanding the immune responses to viral capsids and bacterial pathogens is crucial for improving vaccine design and efficacy. This review explores the complex molecular pathways that underlie vaccine-induced immunity, focusing on the interactions between the immune system and different viral and bacterial antigens. Results:   By examining the cellular and humoral immune responses elicited by viral capsids and bacterial pathogens, we highlight key factors that influence vaccine effectiveness, such as antigen presentation, immune memory, and immune evasion mechanisms. Furthermore, we discuss how these molecular interactions can be modulated to enhance vaccine strategies, providing insight into future vaccine development against emerging infectious diseases. Conclusion:   Through a detailed exploration of the molecular dynamics involved, this article aims to deepen our understanding of vaccine-induced immunity and inform the development of more targeted and effective immunotherapies. https://jmb.tums.ac.ir/index.php/jmb/article/view/560