How does it work?
When the body senses foreign substances (called antigens), the immune system works to recognize the antigens and get rid of them. B lymphocytes are triggered to make antibodies. These specialized proteins lock onto specific antigens. The antibodies stay in a person's body. That way, if the immune system encounters that antigen again, the antibodies are ready to do their job. That's why someone who gets sick with a disease, like chickenpox, usually won't get sick from it again. Antibodies can recognize and lock onto the antigens, but they need help to destroy it, that’s where T cells come in, these destroy antigens tagged by antibodies or cells that are infected or somehow changed, they also help to signal other cells so they can do their job.
References:
Larissa Hirsch. (2019). Immune System. April 17, 2020, de KidsHelath Sitio web: https://kidshealth.org/en/parents/immune.html