![](/content/sites/plus.maths.org/files/styles/small_square/public/abstractpics/5/13%20Jul%202010%20-%2017%3A48/icon-13.jpg?itok=Or3Te5wU)
Vaccination is an emotive business. The furore around the MMR vaccine and autism has shown that vaccination health scares can cause considerable damage: stop vaccinating, and epidemics are sure to follow. But how do scientists decide whether a vaccine and a vaccination strategy are effective and safe? We talk to Paddy Farrington, Professor of statistics at the Open University. You can also read the accompanying article.