[Routine vaccination strategies, reactive vaccination, and pandemic preparedness and response]

Vaccines represent the most important public health tools. In order to ensure the success of an effective and safe vaccine, it is important to implement adequate immunization strategies. Routine strategies, based on children immunization schedules, represent the most commonly utilized approach. Reactive immunization strategies may also be used and be effective especially in response to an outbreak; these strategies include both mass vaccination and ring vaccination, which relies on the identification and immunization of case contacts. A specific role is played by pandemic plan, in which the use of a vaccine may be either proactive, when specific population targets are immunized before the occurrence of an epidemic, or reactive. In conclusion, to successfully control vaccine preventable diseases, it is important to implement adequate vaccination strategies, taking into account the availability of the vaccine, the characteristics of the micro-organism, and epidemic dynamics.