What is the difference between a live virus immunisation and a non live virus immunisation?
Live virus vaccines contain live, but weakened viruses. Examples include the oral polio vaccine and the MMR vaccine. Live virus vaccines actually cause an infection, but because they are weakened (attenuated), they don’t cause disease (usually). Live virus vaccines provide better immunity because the body is responding to an actual infection. Live virus vaccines should not be given to anyone with compromised immunity (e.g. babies and very old people) because there is a small risk of vaccine-associated disease in these individuals. Indeed, the only case of measles I have seen in the past 15 years was vaccine-associated. Killed vaccines contain inactivated viruses. These vaccines provide adequate protection with no risk of infection.
