objective. The book is based on the best available evidence, and Professor Gøtzsche explains when and why we should not have confidence in the science and official recommendations. Some vaccines are so beneficial - and have saved millions of lives – that we should all get them; some are so poor that many healthcare professionals do not use them for themselves or their families; and some are in-between. We must evaluate carefully each vaccine, one by one, assessing the balance between its benefits and harms, just as we do for other drugs, and then form an opinion about whether we think the vaccine is worth getting or recommending to other people. The book focuses on measles, influenza and HPV but discusses also childhood vaccination programmes and whether mandatory vaccination can be justified. Raising critical questions to vaccines is essential because there are still many unresolved issues. For example, we know virtually nothing about what happens when we use many vaccines and what the long-term effects are on the immune system.