infectious agent it is a infection-causing organism. It is also called a pathogen (from the Greek pathos, “disease” and genos, origin”).
The infectious agent is present in our environments, including viruses, bacteria, fungi, protozoa and a series of other pathogenic microorganisms that cause infections.
For a disease to manifest, the infectious agent needs to overcome some of the organisms' natural barriers. These barriers are the invisible and vigilant defense, capable of fighting and destroying the infectious agent is the immune system or immune system.
The transmission of an infectious agent can be passed to our body in different ways: respiratory, salivary, fecal-oral, sexual, placental, or through etiological agents that they are the causative organisms of diseases of parasitological origin such as malaria, rabies, filariasis, Chagas disease, among others, which are transmitted by host animals of the agent.
Infestation by an infectious agent can be fought by prevention, with immunization through the use of a vaccine, consisting of modified antigens, dead or attenuated, potent to stimulate the production of antibodies and the acquisition of memory cells, which constitute the artificial immunization against the disease.