Measles is one of the most contagious of all childhood illnesses. It’s spread through person-to-person contact and respiratory droplets caused by coughing and sneezing. The virus can survive in the air and on surfaces for a couple of hours. Up to 9 out of 10 unvaccinated people who come into contact with someone with measles will get sick. A person with measles is contagious from about one day before they start to feel unwell. This is about 4 days before the rash starts. They will need to stay away from all unvaccinated people for at least 4 days after the rash first appeared. If you child has been near someone with measles, keep them at home until you have spoken with your doctor.