Microorganisms, such as bacteria, viruses, protozoa, fungi, or yeast that invade the body are known as

Pathogens is the answer. Active immunity is the body's continuing to immune and defend against pathogen. A pathogen can be defined in terms of its characteristics to create toxins, enter tissue, colonize, hijack nutrients, and its ability to immunosuppress the host. There are types of pathogens; two of them are bacterial and viral.