When your child is immunised they are helping to protect the health of the whole community. When enough people are immunised against an infection, it is more difficult for it to be spread to those who are not immunised. This is called 'herd immunity' or 'population protection'. This is important because children with some severe medical conditions and allergies (external link to PDF) cannot have certain vaccines. How does herd immunity work? Watch a short animation that explains how herd immunity works:
© NHS Immunisation, Department of Health
If you can't see this animation, you may need to download:
Last reviewed on 26 April 2013