Cancer and your risk of COVID-19

October 18, 2021 Providence Cancer Team


In this article:

  • Cancer and its treatments can weaken your immune system, which may put you at higher risk of getting sick – including with COVID-19.

  • There are many steps you can take to boost your immunity during cancer treatment.

  • Early detection is still key to cancer treatment. Don’t delay life-saving cancer screenings during the pandemic.

Chances are, if you’re actively receiving cancer treatments right now, you’re already aware that some medications and therapies may weaken your immune system – leaving you at a higher risk of catching just about anything from a common cold to the flu and even COVID-19.

Keep in mind that not all cancer treatments weaken your immune system. And, if you’re no longer receiving treatment, your immune system may have rebuilt itself so it can begin to fight off the germs that can cause illness.

Still, you might have some questions as you try to navigate the latest information about cancer and COVID-19. Here, we’ve compiled some critical information to help you separate fact from fiction – and feel confident about getting care when you need it.

Understanding your immune system

You have many “layers” of defense in your immune system. The first is your skin and the mucous membranes in your mouth, nose, throat and eyes. These create a barrier that stops germs from entering your body.

If germs (like the COVID-19 virus) enter your body, your immune system triggers a response to attack and remove the foreign body. That can be through coughing, sneezing, blowing your nose and even a fever to help kill the virus.

The immune response is powered by white blood cells. Many cancer treatments and some types of cancers impact your body’s ability to make enough white blood cells, which weakens your immune response. Some treatments can also damage the skin, including incision wounds from surgery, thinning skin or rashes or punctures to the skin from procedures like placing ports or IVs. Treatments can also damage mucous membranes, which is the lining in the mouth, nose, throat and eyes that helps keep germs out of the body. Damage to the skin or mucous membranes can make it easier for germs to enter the body.

Cancer treatments that may impact your immune system

During treatment, your doctor and care team can help you understand the impact of certain therapies and procedures on your immune system. In general, keep in mind that whether the direct treatment has an impact on your body’s ability to fight off infections or not, it’s important to stay well-rested, maintain good nutrition and stay hydrated to minimize extra stress on your body.


Surgery can increase your risk of infection as it may damage your skin and mucous membranes. Anesthesia may also weaken or reduce the number of immune cells. It could take weeks or months for your body to recover from the effects of surgery. Some surgeries, such as a splenectomy (removal of the spleen) can even impact your body’s long-term immune response. Your spleen helps fight infections, among many other tasks. (A splenectomy is only considered for certain cancer patients, including those with Hodgkin’s and non-Hodgkin’s lymphoma and some types of leukemias.)


Chemotherapy works by slowing down the cell growth and division process – an  important method to controlling rapidly dividing cancer cells. However, it can affect all the cells in your body – from the cells that control hair growth to the number of white blood cells your body can produce. The fewer white blood cells you have, the harder it is for your body to overcome illness. Fortunately, the impact on white blood cells is relatively short. Your body will start to make more white blood cells about 2 to 2.5 weeks after chemotherapy.


Radiation doesn’t typically impact immunity as it’s generally directed to a specific area of the body. However, total body irradiation (TBI) can cause very low white blood cell counts. Radiation can also sometimes damage the skin, making it easier for germs to enter the body.

Targeted therapy

One cancer treatment that generally poses a lower risk of affecting your immune system is targeted therapy. This type of therapy works by attacking a specific cancer or cell enzyme.  Because this therapy does limit its response to certain cells, it does reduce the risk of interfering with how your body responds to infections


Immunotherapy, along with targeted therapy, is one of the many exciting advances in cancer care. It teaches the immune system to recognize and attack cancer cells. This helps protect healthy cells. However, immunotherapy can sometimes change how your immune system works.

Stem cell transplants

Some people with cancer need a stem cell transplant (also called a bone marrow transplant) to replace bone marrow cells that have been destroyed by cancer. Since the treatment preparation can eliminate both red and white blood cells temporarily before they are replenished, there is a short period of time while your body is building back up its defenses where your immune system will be more vulnerable.

Boost your body’s immune response

If you are undergoing any cancer treatment, there are a few simple things you can do to help keep your body’s immune system in fighting order. As always, talk to your doctor about the approach that’s best for you.

  • Protective drugs. There are some prescription medications that can help bolster immunity and your body’s white blood cell count.

  • Eat a healthy diet. Eating isn’t always easy when undergoing cancer treatments, but getting enough calories, nutrients and fat is key to giving your body the energy it needs to stay healthy. A dietitian can help tailor a meal plan for you.
  • Stay active. Regular exercise – even if it’s just walking around the block or gentle stretching – can also help flush out harmful bacteria from the lungs and airways. (Not to mention exercise is a proven way to fight fatigue during treatments!)
  • Get a good night sleep. Your body needs rest to heal and recover every day. That’s especially true during cancer treatments. Research has shown that getting enough shut eye can decrease your overall stress and increase your body’s T cell production.
  • Get the flu shot. It’s important to protect yourself from as many illnesses as possible and a flu shot is safe anytime – even during chemotherapy or radiation.
  • Stick to the basics. This pandemic has taught all of us the importance of following safety precautions that limit the spread of COVID-19. Getting vaccinated, washing hands thoroughly, wearing a mask and staying 6 feet apart from others can help reduce your risk of COVID-19 and other illnesses.

Find answers to common COVID-19 + cancer questions

Still have a question about your risk of COVID-19? Here are a few questions our patients and their families ask us.

Does COVID-19 affect your body differently if you have cancer?

No, COVID-19 does not affect your body differently if you have or have had cancer. The biggest difference is that your immune system may be weaker, making it easier to catch the virus or for an illness to become more severe. It’s important to monitor your health closely and notify your doctor of any new or unusual symptoms.

Should I delay cancer treatment to keep my immune system stronger?

Do not delay care for cancer even during the COVID-19 pandemic. Cancer can be a very serious disease. And outcomes are typically better when cancer is detected and treated earlier.

What should I do if I think I have COVID-19?

If you develop any new or concerning symptoms that could be COVID-19, contact your doctor’s office immediately. Your cancer team will help you monitor symptoms and determine your next steps. There are also treatments (such as monoclonal antibodies) that can help your body fight off COVID-19.

Is the COVID-19 vaccine safe for people with cancer?

Yes, the COVID-19 vaccine is safe for people with cancer. Severely immunocompromised individuals may need to wait until their immune system begins to improve before getting the vaccine. Research also indicates that  cancer patients may benefit from a third “booster” dose of the COVID-19 vaccine.

Stay healthy. Get cancer screenings.

Even as COVID-19 continues to spread throughout our communities, it’s still important to see your doctor regularly. Wellness exams and routine cancer screenings can detect illness and disease in its earliest stages, when it’s easiest to treat.

You can have peace of mind that your healthcare team at Providence is working hard to keep you safe during your screenings. Talk to your doctor to find out if you’re due for a common cancer screening, such as:

  • Breast cancer
  • Colon cancer
  • Prostate cancer
  • Cervical cancer

Learn more about lifesaving cancer screenings.


Find a doctor

Connect with one of our oncologists or cancer care specialists and get recommendations tailored to your diagnosis and treatment. You can also use our provider directory to find a primary care doctor who’s right for you.

Providence in your inbox 

Subscribe to our newsletter to get more educational and inspirational stories from the expert caregivers at Providence.

Related resources

The role nutrition plays during cancer treatments

Don’t delay life-saving cancer screenings

Finding the strength to seek care during the pandemic

Eating to combat cancer: The Providence Thrivorship program

COVID scared to cancer aware

Cancer nutrition myths: Separating fact from fiction

Third dose of COVID-19 vaccine

COVID-19 boosters: Who’s eligible, when?

Providence & iHeart Radio team up to talk about women’s health

This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

About the Author

The Providence Cancer Team is committed to bringing you the most up-to-date insights about treatments, prevention, care and support available. We know cancer diagnoses strain you both mentally and physically, and we hope to provide a small piece of hope to you or your loved ones who are fighting the cancer battle with useful and clinically-backed advice.

More Content by Providence Cancer Team
Previous Article
 It’s not a given: One woman’s journey to get pregnant
It’s not a given: One woman’s journey to get pregnant

A nurse at Providence in Spokane shares how she found hope in her family as she struggled with infertility....

Next Article
Spokane baby boom: 15 Providence maternity nurses pregnant at once
Spokane baby boom: 15 Providence maternity nurses pregnant at once

A story of how 15 nurses working in the same maternity center shared the journey into parenthood together. ...