People with defective immune systems MMR vaccine susceptibility Taking immunosuppressive drugs such as corticosteroids Pregnant women People who are not allowed to get the MMR vaccine People who have active cancer and are receiving chemotherapy or radiotherapy. People who have had an organ transplant and are receiving immunosuppressive drugs. People with active HIV infection .

People with defective immune systems MMR vaccine susceptibility Taking immunosuppressive drugs such as corticosteroids Pregnant women People who are not allowed to get the MMR vaccine People who have active cancer and are receiving chemotherapy or radiotherapy. People who have had an organ transplant and are receiving immunosuppressive drugs. People with active HIV infection .