Cancers tend to wreak havoc with the body’s immune system, particularly cancers of the blood, Schaffner said.
Blood cancers “frequently involve cells that interact with or are a part of the immune system — lymphomas, for example. The disease itself reduces the capacity of the immune system to function normally,” Schaffner said.
The study points out that older age — a known link to severe COVID — takes a back seat to cancer, said one expert.
“A cancer diagnosis seems to trump age as a risk factor for a weaker immune response,” said Dr. Julie Gralow, executive vice president and chief medical officer of the American Society of Clinical Oncology.
The treatments used to cure cancer — chemotherapy, radiation therapy, immunotherapy — also can interfere with immune response, said Dr. Betty Hamilton, interim director of the Cleveland Clinic Blood and Marrow Transplant Program.
“We have had the sense that patients who are immunosuppressed or immunocompromised in some way have less response to the vaccine,” Hamilton said, citing cancer patients as well as patients undergoing organ transplant.
Still, cancer patients should get the COVID vaccine and booster, Hamilton and Schaffner said.
“We do still recommend vaccination for these patients because we do believe that a little bit of protection is better than none,” Hamilton said.
Best bet is to quarantine
But their best bet to stay COVID-safe is to quarantine, and for the people around them to get vaccinated and stick tight to public health recommendations, the experts said.
“If you are one of these people, or one of the people around these people, you have to be careful,” Schaffner said. “Use the masks. Be very careful with social distancing, and avoid crowds. And certainly the people around them should be vaccinated.”
“It’s really important to counsel these patients that they still need to be very careful in public and to wear masks and wash their hands frequently,” Hamilton said.
“My specialty is bone marrow transplant, and so our patients are extremely immunosuppressed,” she said. “Oftentimes after transplant they use these public health measures anyway. Even without COVID, they’ve been using these methods of avoiding crowded places and wearing masks and washing their hands frequently and avoiding people who are ill.”