What is the substance injected into the body that helps protect6 against disease is?

The substance injected into the body that helps protect against disease is called a vaccine. Vaccines contain weakened or inactivated parts of a particular virus or bacterium, or pieces of its genetic material, which stimulate the immune system to recognize and fight the pathogen without causing the disease. This promotes the development of immunity, enabling the body to respond more effectively if exposed to the actual disease in the future.