A live virus vaccine is designed to stimulate the body’s immune system recognize and fight infections caused by the non-weakened form of the virus.
A vaccine made from a live virus has been weakened so it does not cause the disease the virus usually causes.
The currently available live attenuated viral vaccines are measles, mumps, rubella (MMR-II), vaccinia, varicella, zoster (shingles – which contains the same virus as varicella vaccine but in much higher amount), yellow fever, rotavirus, and influenza (intranasal).
Live virus vaccines use the weakened (attenuated) form of the virus.
Killed (inactivated) vaccines are made from a protein or other small pieces taken from a virus or bacteria.
It is not safe for pregnant women or people with weak immune systems to receive a live virus vaccine.
Live viruses also have the potential to shed to others in the community.