Immunotherapy and COVID Vaccine: Your Questions Answered

People with a weakened immune system due to cancer are at an increased risk for poor outcomes from COVID-19. No matter where you are in your treatment plan, vaccination can reduce your risk of developing severe COVID. Vaccination is important even for those with a robust immune system.

The National Comprehensive Cancer Network (NCCN) and the American Cancer Society recommend that people with cancer, including those receiving treatment, get vaccinated as soon as possible. NCCN notes a few exceptions regarding immediacy:

• People getting a stem cell transplant should wait at least 3 months after treatment to get vaccinated.
• People getting CAR T-cell therapy or natural killer (NK) cell therapy should wait at least 3 months after treatment to get vaccinated.
• People with cancer who have major surgery should wait several days to 2 weeks after the procedure to get vaccinated.

Since they weaken the immune system, some cancer treatments reduce — but don’t eliminate — vaccine effectiveness. Even if you’re getting one or more of these treatments, you will gain some protection from the vaccine. Treatments include:

Vaccination combined with protective measures, such as wearing a mask and avoiding large crowds, provides you with more protection from COVID than you would have without them. For that reason, experts strongly recommend vaccination for people with cancer or a history of cancer.

But check with your oncologist first about when you should get vaccinated. If you are currently receiving treatment for cancer, it may be best to wait until your immune system recovers from treatment. This will give you the best chance of mounting a strong immune response.

Both the Pfizer BioNTech and the Moderna mRNA vaccines are appropriate for use in people who take immunotherapy drugs. Neither vaccine is known to be better than the other for this population.

A 2021 study found that the Moderna vaccine was safe for people with solid tumors receiving chemotherapy, immunotherapy, or both. Their response to the vaccine was similar to those who did not have cancer. The groups also saw similar rates of side effects.

A separate 2021 study noted that people with solid tumors who had the Pfizer vaccine had similar antibody levels to those without cancer 6 months after vaccination. In the subgroup of people on immunotherapy, about 87% still had antibodies, compared to about 84% of the control group.

If you cannot get or do not want either of these vaccines, you can also get the Johnson & Johnson (Janssen) vaccine.

Having cancer or taking immunotherapy drugs does not increase the possibility of serious side effects, such as allergic reactions or myocarditis.

Swelling in the lymph nodes under the arm on the same side as the injection site is a potential side effect of vaccination. While temporary, this can be concerning for people with breast cancer and other cancers.

Tenderness and swollen lymph nodes caused by vaccination should subside within a few days to a few weeks. Let a healthcare professional know if the swelling increases or does not go away within this timeframe.

To date, researchers do not know definitively if immunotherapy drugs affect the effectiveness of COVID-19 vaccines, either positively or negatively.

Scientific articles from 2021 and 2022 I suggest that checkpoint inhibitors could theoretically boost your immune response to the COVID-19 vaccine. But both articles also state that no study has demonstrated such an effect.

Some immunotherapy drugs, such as CAR T-cells, may weaken the immune system temporarily. This may make the vaccine less effective. Other types of immunotherapy drugs, such as monoclonal antibodies, should not have this effect.

People with compromised immune systems may find it difficult to generate a robust response to the vaccine, no matter what type of cancer treatment they receive. This may be particularly true for people with blood cancers. For that reason, doing protocols for people who are immunocompromised and have cancer differ from those used for the general public.

To date, no data indicate that the COVID vaccine reduces the effectiveness of immunotherapy medication. But there may be a 17% to 48% risk of side effects due to an overstimulated immune response, according to research.

A case report published in May 2021 suggests the potential for cytokine release syndrome after COVID vaccination in patients taking certain immunotherapy drugs. The study authors state that more data is needed and still favor vaccination for people with cancer.

A 2021 study involving 134 people found no adverse effects from immunotherapy drugs after receiving the Pfizer vaccine. The study’s authors also stressed the need for larger studies and more data, but supported vaccination for people receiving immunotherapy.

However, the impact of certain immunotherapy treatments on your immune system makes the timing of vaccination important. Talk with your oncologist about when you should schedule your vaccine.

People taking immunotherapy drugs should receive an additional primary dose of the vaccine if they have active cancer or are immunocompromised. You may fall into one of these categories if any of the following situations apply:

• You’re on CAR T-cell therapy.
• You’re taking high dose steroids to treat the side effects of immunotherapy drugs (or for any other reason).
• You’re getting cancer treatments such as chemotherapy in addition to immunotherapy.
• You started cancer treatment within 1 year of your first COVID vaccine dose.
• You’re newly diagnosed with cancer or have recurrent cancer, and receive or will receive cancer treatment.
• You have any type of hematologic (blood) cancer.
• You have an immunocompromising condition, such as HIV, in addition to cancer.
• You had an organ or stem cell transplant.
• You contracted SARS-CoV-2 and developed COVID-19 after getting two vaccine doses.

Yes. Getting COVID does not ensure you will not get it again. In fact, with ever-changing variants continually emerging, contracting the virus more than once has become commonplace.

If you’re on cancer treatments that cause you to be immunocompromised, it is vital to get vaccinated, even if you’ve already had COVID. Talk with your oncologist about when you should get vaccinated after having COVID-19.

If you have cancer, you may be more likely to experience serious complications from COVID-19. Cancer treatments, including certain immunotherapy drugs, may affect your scheduling for vaccination. Talk with your oncologist about when you should schedule your vaccines and how many doses you should get.