مجلة الاربعين المحكمة
The immune system protects the human body from disease through several lines of defense, each with its own specificity. Physical barriers, such as the skin, prevent pathogens such as bacteria, viruses and parasites from entering the body. If a pathogen breaches these barriers, the innate immune system responds immediately, but in a non-specific manner. When a pathogen successfully evades the innate immune response, vertebrates have a second line of defense: the adaptive immune system (specific), activated by the innate immune response, the immune system adapts its response during infection to improve pathogen recognition. Human immune responses can change depending on environmental conditions, so many environmental factors influence the Arbaeen march (the focus of our study), which is the fortieth day after the martyrdom of Imam Hussein (peace be upon him). Arbaeen is considered one of the largest gatherings of human beings in the world. It is a great, authentic, and deeply rooted movement, bringing together millions of Muslims from all over the world annually, regardless of their nationalities, colors and languages. Therefore, the scarcity of rest areas, the varying outdoor air quality, and the varying temperatures coincide with the visiting season. However, not all visitors are affected by most environmental factors, as the feeling of comfort in performing these religious rituals supports the immune system, and thus supports better health for the individual (visitor). This study aims to comprehend the influence of environmental agents and interpret the immune responses of visitors of both genders and different ages