CHEKOV: CHEcKpoint Inhibitor effects On SARS-CoV-2 Vaccination

The immune system of cancer patients is affected by their disease but also from side effects of their treatment. A new class of anti-cancer drugs, immune checkpoint inhibitors (ICIs), are very different to all other treatments because they work by directly altering the immune system to target the cancer. These drugs are now used routinely to treat patients with various cancers.

They can also cause side effects that could be enhanced by SARS-CoV2 infection or vaccination. There is very little known about how ICIs impact vaccination against SARS-CoV-2. Given that COVID-19 is likely to circulate for the foreseeable future, it is important to know if current COVID-19 vaccines are effective in patients receiving ICIs.

To address this question, we have been collecting blood samples from melanoma patients being treated with ICIs that were infected during the pandemic. More recently we collected samples from ICI-treated melanoma patients and healthy individuals during the COVID-19 vaccination campaign. We now wish to test these samples to see if vaccination of ICI-treated patients illicits the same magnitude and quality of immune response as observed in healthy individuals, or if different vaccines and/or different vaccine scheduling may be required to protect these patients.

We will also examine if vaccination or infection of patients receiving ICIs could increase the risk of developing the immune-driven side effects that can be caused by these drugs.