Current status and future directions of post-marketing vaccine safety monitoring with focus on USA and Europe.

Vaccine safety research is a key component of public health programs. Regulatory agencies need to be able to make informed decisions. Public health authorities need to respond to vaccine concerns before they turn into large scale scares reducing vaccine uptake and derailing immunization programs. Several post-licensure vaccine safety monitoring systems have been established in the USA and Europe, and methods such as rapid cycle analysis have been developed for real-time detection and analysis of safety issues. Accurate and reliable vaccine product testing and monitoring requires high quality data of populations of 100 million and above depending on the frequency of the event, vaccine coverage, and the time pressure during which data need to be generated. This requires post-licensure safety studies utilizing large linked population based databases of exposure and outcomes. Harmonized methods for development and linkage of these databases across countries need to be further developed, validated and implemented. Concerted action between the US and Europe could move vaccine safety monitoring to today's level of requirements globally and should be pursued. Published by Elsevier Ltd.