Research is revealing a clearer picture of vaccination, immunity, and COVID-19  in cancer patients and other immunocompromised people. 

Since the early phases of the pandemic, scientists and physicians have known these individuals are especially vulnerable to severe disease, complications, and death from COVID-19. However, their immune system responses to SARS-CoV-2 vaccines were unclear, as initial vaccine trials did not include cancer patients. 

The data have since accumulated, illustrating varied responses that tend to be lower than people with unaffected immune systems. Patients with cancer, particularly those with blood cancers, are at increased risk of COVID-19. Blood cancers often cause alterations in immune cells that produce antibodies against the virus.