Immunotherapy is a treatment that stimulates or suppresses your immune system to help your body fight disease or infection.

The field of immunotherapy is rapidly developing as researchers improve their understanding of the immune system’s role in disease.

For instance, it’s used to treat a wide variety of cancers, and is even considered the “fifth pillar” of cancer treatment, along with:

  • chemotherapy
  • radiation therapy
  • targetted therapy
  • surgery

Immunotherapy also plays an important role in treating other conditions, such as immunodeficiency disorders, allergic reactions, and autoimmune diseases, among others.

Keep reading to learn more about immunotherapy, including when it’s used, its types, and potential risks.

The first scientific advancement in immunotherapy is often attributed to two German physicists, Busch and Fehleisen, in the late 1800s. They noticed that tumors regressed after people with cancer had certain bacterial infections, and they later intentionally injected people with cancer with these bacteria to shrink tumors.

In 1891, the “Father of Immunotherapy,” William B. Coley, attempted to treat bone cancer with immunotherapy. Over 60 years later, in 1967, T-cell therapy was discovered, laying the path for modern immunotherapy for cancer.

In 2018, Dr. James Allison and Dr. Tasuku Honjo won the Nobel Peace Prize for developing a type of immunotherapy called checkpoint inhibitors, which led to the Food and Drug Administration (FDA) approving ipilimumab (Yervoy) in 2011. Since then, immunotherapy research has rapidly developed.

Much of the current research focuses on immunotherapy for cancer, but it’s also used to treat many other conditions.

Cancer

Immunotherapy can enhance your immune system’s ability to find and destroy cancer cells.

Every cancer cell has more than 11,000 gene mutations that differentiate it from healthy cells. Some of these mutations make them targets for immunotherapy.

Immunotherapy has been approved or is under investigation for treating many different types of cancer. Some of these include:

Primary immunodeficiencies

Immunotherapy is used to treat some types of primary immunodeficiency. Primary immunodeficiency is a group of more than 200 genetic conditions that impair your immune system.

Some of these conditions include:

According to the Immune Deficiency Foundation, a type of immunotherapy called immunoglobulin replacement therapy is one of the most important and successful therapies for treating primary immunodeficiencies.

Allergic reactions

According to the American College of Allergy, Asthma, and Immunology, immunotherapy may help prevent allergic reactions to substances like bee venom, dust mites, and grass pollen.

Immunotherapy for allergies involves injecting gradually increasing doses of the substance you’re allergic to in order to reduce your immune system’s sensitivity to it.

Autoimmune disease

Autoimmune diseases occur when your immune system attacks healthy tissue, leading to inflammation and tissue damage. The goal of immunotherapy for autoimmune conditions is to block immune activity.

According to a 2025 review, conventional treatment for autoimmune conditions involves taking nonspecific immunotherapies that have broad suppressing effects on your immune system but can also cause side effects.

The authors note that current advances in immunotherapy, such as checkpoint agonists, CAR T-cell therapy, and cytokine targeting, aim to modulate immune activity rather than suppress it.

However, many factors still need to be developed before these are FDA-approved and implemented, such as understanding potential side effects and mitigating high costs.

Tissue and organ transplants

Immunotherapy can be used to dampen the immune system in people receiving transplanted organs to reduce the risk of organ rejection. Immunosuppressants are typically administered in two phases:

  • Induction: Large doses are administered at the time of transplantation.
  • Long-term maintenance: Smaller doses are administered after the transplantation.

According to the National Kidney Foundation (NKF), four types of drugs may be given during the maintenance phase:

  • calcineurin inhibitors
  • antiproliferative agents
  • mTOR inhibitors
  • steroids

Inflammatory disorders

Immunotherapy is used to treat many types of inflammatory disorders, many of which are also classified as autoimmune disorders. Some examples of medications include:

  • tocilizumab (Actemra), which is used for rheumatoid arthritis, juvenile idiopathic arthritis, and adult-onset Still’s disease
  • anifrolumab (Saphnelo), which is used for systemic lupus erythematosus
  • etanercept, which is used for rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, psoriasis, and psoriatic arthritis
  • inebilizumab (Uplizna), which is used for neuromyelitis optica spectrum disorder

Infectious disease

Research on immunotherapy for treating infectious diseases isn’t as advanced as it is for cancer immunotherapy. That said, recent advances have been made for infectious diseases such as:

Immunotherapy works by either suppressing or stimulating your immune system. Different types of immunotherapies achieve this in different ways.

Five primary types of immunotherapy are used to treat cancer:

  • Checkpoint blockade therapy: These drugs block your “immune checkpoints,” which limit your immune system’s aggressiveness.
  • Adoptive cell immunotherapy: This therapy enhances T cells’ ability to recognize cancer. T cells are a type of white blood cell that plays an important role in your adaptive immune system.
  • Oncolytic immunotherapy: These medications contain proteins that bind to cancer cells to signal for your immune system to destroy them.
  • Cancer vaccines: These vaccines stimulate a stronger immune reaction against cancer cells.
  • Cytokines: These medications enhance part or all of your immune system.

Other types of immune therapy include:

  • Allergen shots: Allergen shots contain a small amount of an allergen to help your body produce antibodies to the substance and reduce your allergy symptoms.
  • Intravenous (IV) immunoglobulin therapy: This therapy involves the infusion of donor antibodies through an IV line to treat certain inflammatory and autoimmune conditions.
  • Immunosuppressive drugs: These drugs suppress your immune system activity to manage some autoimmune conditions and prevent organ rejection in people who receive transplants.
  • Helminth therapy: This experimental treatment involves administering helminth parasites to treat some autoimmune and inflammatory conditions. It’s not FDA-approved at this time.
  • Transfer factors: Transfer factors are proteins produced inside your immune system. They’re under investigation for treating conditions such as herpes, yeast infections, and stage 3 HIV.
  • Immunization: Vaccines prevent infections by teaching your immune system to recognize certain infections. Many vaccines have been developed to treat conditions such as:

Immunotherapy is an effective treatment for many different conditions and is under investigation for others.

For instance, it may help manage some types of cancer caused by viruses, such as:

A 2019 review also found evidence to support:

The American Academy of Allergy, Asthma, and Immunology states that allergy shots may potentially decrease symptoms of many allergies. Effectiveness seems to be linked to both the dose and the timing of treatment.

Side effects vary by treatment and can vary from mild to life threatening. According to the American Cancer Society (ACS), some possible side effects may include:

Other side effects not listed here can also occur. A doctor or healthcare professional can give you the best idea of what to expect for your type of treatment.

A doctor may recommend immunotherapy if you have cancer or another condition for which it is approved. Immunotherapy is worth considering if research shows it is linked to better outcomes for your condition.

A doctor may recommend against immunotherapy if you have certain health concerns. For example, doctors are often hesitant to prescribe immunotherapy for cancer treatment in people with autoimmune diseases.

A doctor can help you decide whether the benefits outweigh the risks of side effects and the cost.

Medical Perspective

“People taking immunosuppressants may wish to consider optimizing their health by eating nutritious foods, exercising regularly, and preventing infections with good hygiene and other precautions to limit exposures to contagious illness. It’s also important to follow the recommended vaccinations, health screenings, and treatment plans as discussed with their healthcare team.”

— Mia Armstrong, MD

Learn more about how to naturally support your immune health.

Quotes represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Immunotherapy is a type of therapy that stimulates or suppresses your immune system. Immunotherapy research is rapidly advancing.

It’s used to treat many different types of cancer and other conditions such as autoimmune diseases, allergic reactions, and infectious diseases.

A doctor can help you determine whether you might benefit from immunotherapy. They can also advise you about any clinical trials examining immunotherapy for treating your condition.