What Does It Mean to Be Immunocompromised?

In the past several years, the CDC has identified groups of people who are “at risk” for severe COVID-19 disease. This includes adults over 50 years old, people with underlying medical conditions, and people who are immunocompromised. But what does it mean to be immunocompromised? And how do you know if you are?

What is the definition of ‘immunocompromised’?

Being immunocompromised means that your immune system is weakened. This can happen either because of a disease or a medication you take. It means you’re more likely to get an infection. It also means you’re more likely to have a severe illness from that infection compared with someone whose immune system is working well (this is known as being immunocompetent). 

You can become immunocompromised in one of these two ways:

• Immunosuppression is when your immune system is weakened with medications, like after an organ transplant.  

• Immunodeficiency is when your body can’t make enough of certain blood cells to defend itself against infection. 

Some people are born with an immunodeficiency (primary immunodeficiency). A healthcare provider will usually pick this up when the individual is still a child. If this is you, you will know about it. 

Secondary, or acquired, immunodeficiency is the much more common kind in adults. It can be caused by life events, diseases, and medications. 

What health conditions can cause you to be immunocompromised?

If you have a health condition that affects your immune system, it’s possible that you might be immunocompromised. 

Health conditions that can cause secondary immunodeficiency include:

• Autoimmune disorders: This is when your immune system acts against your own body. Common autoimmune disorders include Type 1 diabetes, lupus (SLE), multiple sclerosis, inflammatory bowel disease, and rheumatoid arthritis.

• Chronic health problems: Many chronic diseases can also cause immunodeficiency, like Type 2 diabetes, kidney failure, liver cirrhosis. 

• Infections: Certain bacterial, mycobacterial, and viral infections can cause immunodeficiency. These include tuberculosis, HIV/AIDS, and measles. 

• Cancer: Any type of cancer can make you immunodeficient, like solid (organ) cancers and blood cancers such as Hodgkin’s disease, leukemias, and myelomas. Chemotherapy or radiation therapy for cancer can make you immunocompromised, too. 

• Not having a spleen: Not having a spleen (asplenia) or having reduced spleen function (hyposplenism) can cause immunodeficiency. This can happen because of physical trauma or sickle cell disease, among other causes. 

• Serious burns: Significant burns can lead people to become immunocompromised. 

Being pregnant can cause changes to your immune system, too. Though you aren’t technically immunocompromised during pregnancy, it can increase your risk of getting very ill from certain infections — including COVID. 

Certain life experiences and lifestyle choices can also weaken your immune system. This includes stress, exposure to environmental toxins, tobacco smoking and alcoholism, and even normal aging. 

Can medications cause you to become immunocompromised?

Yes. Some types of medications can cause immunodeficiency. 

Certain medications — called immunosuppressants — make your immune system weaker on purpose. This can be helpful in certain situations, like if you have an autoimmune condition or get an organ transplant. And other medications cause immunosuppression as a side effect. 

Medications that can weaken your immune system include:

• Chemotherapy or radiation for cancer

• Medications that treat autoimmune disorders (like corticosteroids, cyclosporine, methotrexate, azathioprine, and biologic therapies like rituximab and etanercept)

• Medications that destroy bone marrow before a transplant

• Medications to prevent or treat graft-versus-host disease, a rare and serious condition that can happen after bone marrow transplant when donor cells attack the recipient’s cells

• Medications that prevent or treat rejection after an organ transplant (for example, mycophenolate, tacrolimus, or cyclosporine) 

What are symptoms of being immunocompromised? 

Most people who are immunocompromised will know they are because their healthcare provider has told them either during childhood or as they were managing a serious medical condition.

Being immunocompromised is not an all-or-nothing deal. Some people have mild symptoms; others have life-threatening ones. Here are some of the symptoms of a weakened immune system:

• Having more frequent infections

• Having more serious infections 

• Having rare infections

• Taking longer to fight off common infections 

If you think you might be immunocompromised, you’ll need a thorough consultation with a physician, a physical examination, and a range of lab tests to diagnose the problem. If lab tests show that you’re immunocompromised, your provider will want to find the cause. This can involve many more tests, depending on your individual circumstances and what your care team thinks might be going on. 

Should you wear a face mask in public if you’re immunocompromised?

The CDC recommends that people who are immunocompromised (even those who have been vaccinated) wear a mask in public places, unless your healthcare provider tells you otherwise. If possible, try to avoid crowded or poorly ventilated indoor places.

If you’re not sure if you’re immunocompromised, check the list of causes above. If you have one of the conditions listed or think you might, check with your provider about whether you are “at risk” for severe COVID illness. 

Should you get a COVID vaccine if you’re immunocompromised?

Yes. According to the CDC, people who are immunocompromised can — and should — get the COVID vaccine. The approved COVID vaccines do not contain living organisms, and they can’t infect you with the virus that causes COVID. 

If you’re immunocompromised, keep these things in mind:

• Data is limited on COVID vaccines in people with weakened immune systems because clinical trials didn’t include many people who are immunocompromised. 

• Even if you’re fully vaccinated, you may not be fully protected. In some immunocompromised people, studies show that the vaccine may not be as effective. This may include some people with solid-organ transplants, certain types of lymphoma or leukemia, and some with autoimmune diseases on certain medications (like rituximab and mycophenolate). This is why the CDC recommends some immunocompromised people get a third or fourth vaccine dose (more on that below) as part of their initial series. 

• More research is needed to fully understand how the COVID vaccine affects immunocompromised people and the type of immune response they develop.

• After being vaccinated, you may need to continue taking precautions. 

How many COVID vaccine doses do you need?

The CDC recommends that people who are moderately to severely immunocompromised should get a third vaccine dose as part of their initial series. Some people may also need additional vaccines. 

Here are the current COVID vaccine recommendations for moderately to severely immunocompromised people as of September 2023:

• If you’ve never been vaccinated: Get a 3-dose series of the updated 2023-2024 Moderna or Pfizer COVID vaccine. 

• If you’ve had an mRNA vaccine in the past: Get 1 or 2 doses of the updated 2023-2024 Moderna or Pfizer vaccine, depending on how many doses you’ve had in the past. 

Your provider can help you figure out if an additional vaccine dose is a good idea for you. 

What else can you do to protect yourself from COVID?

If you’re immunocompromised, it’s important to protect yourself from COVID infection. Here are some tips to keep in mind:

• Stock up on supplies (a supply for 14 to 30 days) in case you need to self-isolate.

• Try to avoid crowded, indoor settings as much as possible — especially if there’s poor ventilation. 

• Avoid people who are ill. If someone in your home is sick, stay away from them if possible. 

• Wash your hands with soap and water, or use hand sanitizer often. 

• Clean and disinfect your home and car regularly, especially items you touch often, like doorknobs and car handles, steering wheels, light switches, cell phones, and keyboards.

• Brush your teeth at least twice a day. The mouth can be a source of infection.

• Support your overall health by eating a balanced diet. 

• Be physically active by walking every day (but avoid groups or crowds).

• Get enough sleep.

• Manage stress and worry. Stress and worry are normal responses, but they can weaken your immune system. Try meditation, yoga, a gentle walk, or a creative hobby. Find what works for you.

The CDC also has a great worksheet that can help you build a personal COVID action plan. Having an action plan can help protect and prepare you in case of an exposure or COVID infection. 

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Written by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. An experienced and dedicated pulmonologist and hospitalist, she spent a decade practicing and teaching clinical medicine at academic hospitals throughout London before transitioning to a career in health education and health technology.

Reviewed by:

Sarah Gupta, MD

Sarah Gupta, MD, is a licensed physician with a special interest in mental health, sex and gender, eating disorders, and the human microbiome. She is currently board certified by the American Board of Psychiatry and Neurology.

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