November 01, 2021

Should I keep away from someone with a compromised immune system if I receive a vaccine?

Q: Should I keep away from someone with a compromised immune system if I receive a live vaccine?

A: In most cases, your getting a live vaccine isn't a danger to friends and family who have compromised immune systems. Many diseases and disease treatments can suppress the immune system, including cancer and chemotherapy, drugs for autoimmune diseases, drugs given after an organ transplant, and corticosteroids.

Live vaccines are made from a "wild" virus or bacterium that is weakened (attenuated) but can still grow and create a strong and long-lasting immune response. In contrast, inactivated vaccines use a killed (inactive) version of a germ. Examples of live virus vaccines include the:

  • Combined measles-mumps-rubella (MMR) vaccine
  • Varicella vaccine, which helps prevent chickenpox
  • Rotavirus vaccine
  • Yellow fever vaccine
  • Nasal influenza vaccine (FluMist)

No currently available COVID-19 vaccines contain live virus.

If you don't have a weakened immune system but live with or are in prolonged or intimate contact with someone who does, the risk is generally minimal that you will transmit vaccine virus to them.

However, if this person is so immunocompromised that he or she needs to be in a protective environment, such as a special hospital room with high-flow ventilation and filtration, avoid FluMist. Instead, get the flu shot, which is an inactivated vaccine.

In addition, if a person develops a vaccine-related rash after receiving the varicella vaccine, he or she should avoid contact with people with weakened immune systems, as they can develop a severe reaction if exposed to wild-type varicella.

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