Immunology is the science of body systems that protect against infection. It's thanks to immunology that we're able to treat and prevent so many diseases today.
Immunology is formed by adding the suffix -ology, or "science," to immune, or "exempt from a disease." Scientists and doctors who specialize in immunology study the way our immune systems function (and sometimes malfunction) as they work to defend us from viruses and bacteria. Immunologists are also instrumental in creating vaccines against new diseases and promising treatments like cancer immunotherapy, which boost the patient's own immune system.