BACKGROUND: Vaccines are very effective medical tools for disease prevention and life span increase. Controversies have raised concern about their safety, from autism to polio vaccine contamination with simian virus 40 (SV-40). Hysteria surrounding vaccine-associated risks has resulted in a declining number of vaccinations in developed countries. Outbreaks of vaccine-preventable diseases (e.g. measles) have occurred in Europe and North America, causing also some causalities. OBJECTIVES: In this review, data on safety and efficacy of vaccines are discussed, showing that the benefits of vaccines far outweigh the risks and that it is important to comply with vaccination protocols, to avoid spreading of severe, preventable diseases. METHODS: ...