How can we immunize patients with malignant disease against Covid-19?

All patients with active or prior malignant diseases should be fully vaccinated to prevent SARS-CoV-2 infection. Medical treatments may interfere with the efficient immune response, but vaccination is still recommended even in immunocompromised populations. People who undergo chemo-, or radiotherapy should be vaccinated between treatment cycles, when immunosuppression from treatment is minimized. For those who recovered from coronavirus disease or received Covid-19 vaccination prior to stem cell therapy, a repeated vaccination is recommended with a full primary series at least three months after the transplant. The measure of response to vaccination can be estimated on the basis of titre of neutralizing antibody level. Patients who can not be immunized by vaccines at all might benefit from plasma therapy or passive immunization with neutralizing monoclonal anti-SARS-2 antibodies.