COVID-19 vaccines may boost the effectiveness of a type of cancer immunotherapy treatment called immune checkpoint inhibitors. This is the finding of a recent study published in the journal Nature, which suggests that patients with advanced melanoma skin cancer and lung cancer may live longer if they get at least one COVID-19 shot before receiving immune checkpoint inhibitor therapy.
“What researchers saw is that patients who had received a COVID-19 vaccine within 90 to 100 days of undergoing immune checkpoint inhibitor therapy had a much more robust response compared to those who had not received a vaccine,” says Sanjeet Singh Dadwal, M.D., chief of the Division of Infectious Diseases at City of Hope® Cancer Center Duarte.
In this article, Dr. Dadwal shares more about this study’s findings, answering questions like:
- What are immune checkpoint inhibitors?
- COVID vaccines and cancer immunotherapy: What’s the link?
- Should cancer patients get a COVID-19 shot?
- Should COVID-19 vaccines be timed differently in cancer patients?
If you or a loved one has been diagnosed with cancer and are looking for a second opinion, call us 24/7 at 877-460-4673.
What Are Immune Checkpoint Inhibitors?
Cancer immunotherapy is the term used to describe treatments that help the body fight cancer by supporting or boosting a patient’s natural immune system. Immune checkpoint inhibitors are a type of immunotherapy. But how do they work?
- The body’s T cells, which are a type of immune cell, have proteins on their surface that create “checkpoints”— essentially, a way for T cells to tell whether they should attack diseased cells.
- Some cancer cells can “turn off” these checkpoints, allowing them to trick the body’s immune response into ignoring them.
- Immune checkpoint inhibitors work by helping reactivate these checkpoints, so that T cells can detect and fight cancer.
COVID Vaccines and Cancer Immunotherapy: What’s the Link?
According to a study published in 2025, patients being treated for advanced skin or lung cancer showed a more positive response to immune checkpoint inhibitor therapy if they had also received a COVID-19 mRNA vaccine within the previous 100 days.
“The results showed that even one COVID-19 shot boosted immune checkpoint inhibitor activity,” explains Dr. Dadwal. This is in part because the vaccine boosts our natural, or innate immune responses.
“Innate immunity can be stimulated on a cellular level by things like infection, but also by vaccines like the COVID-19 mRNA shot,” he adds.
While more research is needed, Dr. Dadwal shared some of the study’s promising initial findings, including:
- Significantly improved survival rates among advanced skin and lung cancer patients who had received at least one COVID-19 shot
- Nearly double the survival rate for patients with advanced lung cancer who had received at least one COVID-19 shot
“What’s happening at a cellular level is that the vaccine is ‘waking up’ the immune system, which helps immune checkpoint inhibitors attack tumor cells,” says Dr. Dadwal. As well as promoting the body’s natural immunity, “the effects of the vaccine are to reprogram the body’s adaptive immunity, which is what happens when your cells adapt to new stimulus.”
Should Cancer Patients Get a COVID-19 Shot?
Staying up to date on vaccines is a good idea for most cancer patients, according to Dr. Dadwal.
“Anybody with cancer who is undergoing chemotherapy should be up to date with COVID-19 shots, because if they get COVID, that will delay their chemotherapy sessions,” he says. The same is true for many annual shots, including those targeting flu and pneumococcal infections.
“However, we are still far away from saying that the COVID vaccine should be given with every immune checkpoint inhibitor every time to boost its response,” Dr. Dadwal says. “In the meantime, patients should ensure they get their preventative COVID vaccine as needed.”
Should COVID-19 Vaccines Be Timed Differently in Cancer Patients?
Patients should talk to their cancer care team about which vaccines they may need to have before treatment begins and how to time them. While most cancer patients benefit from being up to date on preventive shots like those targeting flu or pneumococcal infections, this may vary on a case-by-case basis.
When it comes to COVID-19 vaccination, Dr. Dadwal says: “A patient might benefit from asking their oncologist whether the shot might boost their immune response to cancer. And if you need to get vaccinated regardless, maybe plan to have that shot closer to your immune checkpoint inhibitor therapy.”
If you or a loved one has been diagnosed with cancer and are looking for a second opinion, call us 24/7 at 877-460-4673.