Live vaccines have a weakened version of the disease-causing microbe. It doesn’t make you sick and may work better to teach the immune system to protect against that disease. Live vaccines include nasal flu vaccine, live shingles (Zostavax®) and chickenpox, yellow fever, oral polio, MMR (measles, mumps, and rubella) and others. When you’re on an immunosuppressant drug, live vaccines may increase the risk of getting the illness that you’re being vaccinated against. Killed or inactivated, sugar, and protein vaccines are considered safe.