Opsonic therapy is a medical treatment aimed at improving the immunity of an individual against a specific disease. There are several synonyms for opsonic therapy including immunotherapy, biological therapy, antibody therapy, and passive immunization. Immunotherapy involves the use of vaccines, monoclonal antibodies, and cytokines to enhance the natural immune response of the body. Biological therapy is a more general term encompassing the use of natural or artificial materials to treat disease. Antibody therapy involves using specific antibodies to target and neutralize harmful pathogens. Passive immunization involves the transfer of specific antibodies from an immune donor to an individual to provide temporary protection from disease. These therapies are becoming increasingly popular in the field of medicine due to their potential to treat a wide range of illnesses.