Third case of measles at Perth school

A third case of measles has been confirmed at a Perth Steiner school where more than half the students may not have been vaccinated against the disease.

A third student at Perth's Waldorf School has been infected with measles the day after the health department held a free clinic offering the vaccine to students.

The school became the centre of a possible measles outbreak two weeks ago when an unvaccinated year 10 student returned from Italy with the disease, prompting the health department to warn possibly half of the students at the Steiner school had not been vaccinated.

Free on-site measles, mumps and rubella vaccinations were given to students on Thursday, following the resignation of the schools principal Jean Michael David after it was revealed he stood as a candidate for the Victorian 2014 election on an anti-vaccination platform.