Zainol Akhbar Zainal
Faculty of Pharmacy, University of Cyberjaya, 63000 Cyberjaya, Selangor, Malaysia
Introduction
The existence of pathogens are detected by the immune system’s components when the immune cells mobilized to the site of an infection. The function of immune system is to recognize the nature of pathogen, its strength for interrelated cells and molecule for combating it efficiently (Alberts et al., 2002). Pathogens can be remembered by immune system to which it has been exposed one time, can create a more efficient response when its re-exposure occurs. For survival against pathogens, necessary things are, Pathogen recognition, specific immune response, its power of amplification, its withdrawal and recalling. It can classify into two parts as either innate immune system and adaptive immune system. Innate immune system is always present in the body and it protects human body against all pathogens without specialization on particular pathogen, while adaptive immune response stores information about infections occurred in past and it provides pathogen specific defence to the body (Lu et al., 2020)