Adverse events following immunization: is this time for the use of WHO causality assessment?

In recent years, public health authorities in industrialized countries have noted an increase in the numbers of parents choosing not to have their children vaccinated and in the activities of 'antivaccination' movements. Doubts about vaccine safety and lack of surveillance of adverse events following immunization (AEFI) are the most frequent themes proposed by antivaccination movements. This editorial aims to critically analyze the use of AEFI assessment procedures among national health authorities and public health researchers. In fact, the WHO recommended and published a systematic and standardized causality assessment process for serious AEFI, providing a method for individual causality assessment to be used by staff of national immunization programs, regulatory authorities and pharmacovigilance or surveillance departments. The last update was published in March 2013 but to date, an Internet search reveals no information or reports on AEFI surveillance that uses the WHO AEFI causality assessment.