Stewart Cole is the head of the Pasteur Institute here in Paris, which spends its time researching and trying to tackle the spread of virus or disease. HIV, cancer, diphtheria, tetanus and tuberculosis are all tackled by the institute as it tries to keep the lives of thousands or even millions of people safe every year. Among other major issues is the battle to persuade some sceptics that vaccines, particularly nowadays for measles, are safe. Stewart Cole spoke to us for today's Perspective.