The CDC, American Cancer Society, and National Comprehensive Cancer Network recommend chemotherapy patients get a COVID-19 vaccine [Comirnaty (Pfizer), Spikevax (Moderna) or Novavax]. However, there is a chance people receiving chemotherapy will mount a smaller immune response following COVID-19 vaccination. You should talk with your doctor if you have any concerns and to make sure medications won’t interfere with the vaccine. People who receive a stem cell transplant or CAR T-cell therapy should wait at least 3 months after treatment to get vaccinated.
Chemotherapy patients should follow the COVID-19 vaccination recommendations for people who are moderately or severely immunocompromised. They should also use these additional guidelines to stay safe from COVID-19 after getting the shot: https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/immunocompromised.html