Immunotherapy

Immunotherapy, also known as biological therapy or biotherapy, encompasses a diverse set of therapeutic strategies that harness or modify the immune system to prevent, control, or eliminate disease. In its narrowest definition, immunotherapy refers to treatments designed to stimulate or guide the immune system to recognize and fight cancer, often by enhancing or restoring immune responses to eradicate malignant cells while sparing healthy tissue. A broader definition of immunotherapy applies beyond oncology, including strategies to stimulate or suppress immune activity against other diseases such as autoimmune disorders, infectious diseases, and allergies. These approaches may involve vaccines, immune modulators, or monoclonal antibodies designed to alter immune responses, either to boost protection against pathogens or to reduce damaging inflammation. Immunotherapy includes both passive methods, like monoclonal antibodies that mark abnormal cells for immune destruction, and active methods, such as cancer vaccines, immune checkpoint inhibitors, adoptive cell transfer, and cytokine therapies. Advances in immunotherapy have transformed the treatment landscape for cancer and are increasingly applied to a wider range of conditions, improving outcomes for many patients, though responses can vary depending on disease type, genetic background, and environmental factors. Cell-based immunotherapies are effective for some cancers. Immune effector cells such as lymphocytes, macrophages, dendritic cells, natural killer cells, and cytotoxic T lymphocytes work together to defend the body against cancer by targeting abnormal antigens expressed on the surface of tumor cells. Vaccine-induced immunity to COVID-19 relies mostly on an immunomodulatory T-cell response. Therapies such as granulocyte colony-stimulating factor (G-CSF), interferons, imiquimod and cellular membrane fractions from bacteria are licensed for medical use. Others including IL-2, IL-7, IL-12, various chemokines, synthetic cytosine phosphate-guanosine (CpG) oligodeoxynucleotides and glucans are involved in clinical and preclinical studies.