The Body's Response to an Infection



The body localises and controls the infective agent through the activation of phagocytic cells and the generation of pro- and anti-inflammatory mediators while simultaneously initiating the repair of injured tissues. This process is known as inflammation, the body's initial response to the presence of an infective agent. During inflammation, the immune response increases vascular permeability to allow the complement system, which is involved in the destruction of the infective agent, to easily access the site of infection.

Phagocytic cells, such as macrophages and neutrophils, are recruited to the infection site, where they engulf and destroy pathogens. Pro-inflammatory mediators, like cytokines, signal an immune response, while anti-inflammatory mediators help to regulate and eventually resolve the inflammation. Endotoxins released by the infective agent further increase vascular permeability by activating both the complement and coagulation cascades, enhancing the immune system's ability to reach and neutralize the threat.

This coordinated response not only targets and eradicates the infective agent but also initiates tissue repair mechanisms to heal any damage caused by the infection. By understanding the intricate processes involved in the body's inflammatory response, we can better appreciate how the immune system works to protect and heal the body from infections.

CPD time1m
First Published03 December 2019
Updated02 December 2019
30 January 2026
Learning Tools
Infectious Diseases
Infection Prevention and Control