1. Ada
  2. COVID
  3. COVID-19 and Cancer

COVID-19 and Cancer

Written by Ada’s Medical Knowledge Team

Updated on


  • Cancer puts you at risk of severe illness due to COVID-19.
  • Taking preventative measures against COVID-19 is vital for cancer patients.
  • The COVID-19 vaccine is recommended for those with cancer.

Having COVID-19 and cancer can put you at risk of severe illness. This is because cancer and cancer treatments compromise the immune system, which is the natural defense system of your body against viruses such as the coronavirus. In this article, we’ll discuss the risks of cancer patients if they get COVID-19 and the best practices surrounding vaccination and infection.

Is cancer considered a high risk for COVID-19? 

COVID-19 may be dangerous for cancer patients. This is because cancers and treatments for cancer can weaken your immune system. The risk of severe symptoms and complications due to COVID-19 is higher for those currently undergoing cancer treatment and those who have had cancer in the past, as as cancer survivors will be immunocompromised for variable periods of time after they complete treatment. Notably, blood cancers can increase the risk of severe illness from COVID-19, as they often cause decreased levels of immune cells. 1

The immune system is a group of cells and organs that work together to find, attack, and flush out viruses and bacteria that have invaded the body and may cause infections. In healthy individuals, the immune system will activate and start attacking the virus in case of an infection with the coronavirus. For those with a weakened immune system, such as people with cancer or people being treated for cancer, the immune system can’t defend the body properly, affecting the severity of the disease. There are a few ways in which cancer can increase the risk of severe symptoms caused by COVID-19: 2

  • Cancer can interfere with the way your immune system should normally work.
  • Cancer itself can affect the bone marrow, where blood cells are made. This will affect the white blood cells, which are vital in fighting off infections. You can get especially sick from COVID-19 if you have leukemia or lymphoma.
  • Tumors can damage the body's natural barriers, which prevent viruses or bacteria from entering the body.
  • Tissue that has been damaged by cancer may be more prone to infections.
  • Cancer which affects organs vital to the immune system, such as the spleen, can cause long-term damage to your immunity.
  • Radiation therapy, chemotherapy, and immunotherapy also affect the cells that form part of the immune system, which makes you more vulnerable to infections. Especially chemotherapy can cause a decrease in a specific type of white blood cells crucial to the immune system, called neutrophils.

The effects of cancer and its treatment on the immune system depend on several things, such as: 2

  • Which chemotherapy was used
  • The dose of the chemotherapy
  • How often you’ve received chemotherapy
  • How many times you’ve been treated for cancer already
  • Your age
  • Your diet
  • The type of cancer you have
  • The stage of cancer you have

Can you get the COVID-19 vaccine if you have cancer?

The COVID-19 vaccine and cancer have been the subject of many studies. The CDC recommends staying up-to-date with your vaccination and booster shots, especially If you run a higher risk of severe complications due to COVID-19. 3 4

COVID-19 vaccination should only be delayed for cancer patients who have just had a stem cell transplant or CAR T-cell therapy until at least 3 months after treatment. This is due to the fact that they typically also receive immunosuppressive therapy during the period and vaccination during the most immunosuppressed state isn’t very effective. All other patients who are being treated for cancer should get vaccinated as soon as possible. Vaccination against COVID-19 does not interfere with the therapy you’re receiving for your cancer, instead, it'll help decrease your risk of severe symptoms and complications due to an infection with the coronavirus. 1 3

Apart from those currently being treated for cancer, the CDC also strongly recommends COVID-19 vaccination for cancer survivors. This is because people who have survived cancer usually have weakened immune systems, which may put them at risk for severe illness caused by the coronavirus.

The vaccines against COVID-19 that are available have been studied extensively and underwent intensive monitoring for safety and effectiveness. There has been no scientific evidence that COVID-19 vaccines might cause cancer, lead to disease progression or recurrence of cancer. 3

What to do if you’re a cancer patient with COVID-19? 

If you have cancer and you’re experiencing symptoms of COVID-19, then you should get tested as soon as possible. This can be done using a PCR test or an antigen test. Both require a swab from the back of the throat or the nose, which can then be analyzed. Getting tested for COVID-19 is the only way to know whether or not you’ve been infected with the coronavirus. Testing ensures that you can get the proper treatment and not spread the virus to others. 1

COVID-19 treatment is available for people with cancer who are likely to get severely ill due to the infection with the coronavirus. Suppose the results of your COVID-19 test come back positive. In that case, contacting your health provider as soon as possible is essential, as you may be eligible for antiviral medication to support your immune system. This treatment must be started early to be effective, so it's crucial to get tested as soon as possible if you experience any of the symptoms of COVID-19.

If you get COVID-19 during chemotherapy or another cancer treatment, your cancer treatment may need to be paused or modified while you’re receiving treatment for COVID-19. Your healthcare provider should consider any potential interactions between the antiviral medication for COVID-19 and your cancer treatment. 1

Treatments: What are the ways to protect yourself if you have cancer and are at high risk for severe COVID? 

People with cancer can protect themselves against COVID-19 by following the same measures as others, being: 6

  • Washing your hands regularly and thoroughly with water and soap.
  • Avoiding touching your face with unwashed hands.
  • Improving ventilation in indoor spaces.
  • Avoiding contact with people who are sick or who have symptoms.
  • Wearing a mask that fits well, covering both nose and mouth. Masks can set a barrier for the particles you breathe, cough, or sneeze out. The N95 masks provide higher protection as they fit closely on the face and filter out particles, including the coronavirus.
  • Keeping a safe distance from others.
  • Vaccination and keeping vaccination up-to-date with the recommended booster shots. 

Wrapping up 

Having cancer and COVID-19 at the same time can cause severe illness. This is because the immune system of cancer patients is often compromised due to therapy or the nature of the cancer. In order to protect yourself and those around you, it’s essential to take preventative measures and get tested if you’re experiencing symptoms. 


Q: Can a cancer patient survive COVID-19?
A: Cancer patients can survive COVID-19, although they’re at risk of falling severely ill due to the infection with the coronavirus. This can lead to hospitalization and death in some cases. 

Q: Does chemo kill COVID-19? 
A: Chemotherapy does not kill the coronavirus. However, it weakens the immune system, which can increase your risk of severe illness due to COVID-19.

Q: What happens if you get COVID-19 during chemo? 
A: Depending on which type of cancer treatment you’re receiving, your treatment might be modified or paused while you’re getting treated for COVID-19. 

Q: Should cancer patients wear masks against COVID-19?
A: Using masks is a preventative measure that sets an additional barrier against the coronavirus. As cancer patients are at a higher risk of severe symptoms and complications due to the coronavirus, it’s advised to use one.