Immune serum is similar to a vaccine, used to enhance immunity against dangerous diseases, especially infectious diseases. It can save lives in critical cases.

When bacteria and viruses invade the body, antibodies fight them. In an immune response, antibodies have three main roles: binding to antigens, activating the complement system, and mobilizing immune cells.

Certain infections and some disorders can be identified by antigen and antibody testing. So what are antigens and antibodies?