Active surveillance for adverse events following immunization

Abstract

Comprehensive surveillance of adverse events following immunization (AEFI) is required to detect potential serious adverse events that may not be identified in prelicensure vaccine trials. Surveillance systems have traditionally been passive, relying upon spontaneous reporting, but increasingly active surveillance and supplemental strategies are being incorporated into vaccine safety programs. These include active screening for targeted conditions of interest (e.g., hospitalization), monitoring of new data sources and real-time methodologies to detect changes in vaccine safety data in these sources. The role of improved causality assessment in AEFI surveillance is discussed, with its important role in determining whether a temporal association may have occurred by chance alone. Strong local vaccine safety networks are required to support national immunization programs, with recent progress in developing a framework for low- and middle-income countries. Global collaboration is increasingly required to address challenges in active AEFI surveillance, particularly for rare serious adverse events.

Keywords::

• active
• adverse
• event
• immunization
• surveillance

Financial & competing interests disclosure

NW Crawford and JP Buttery have acted as chief investigators for epidemiological studies sponsored by vaccine manufacturers (CSL) and serological testing (Merck). All payments, including for sitting on advisory boards (NW Crawford), data safety monitoring boards (JP Buttery), lecturing (NW Crawford) and travel expenses for attendance at scientific meetings, are paid directly to an administrative fund held by Murdoch Children's Research Institute. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Adverse events following immunization surveillance systems have traditionally been passive, relying upon spontaneous reporting after vaccine introduction to a national immunization program or private market.

• Increasingly, active surveillance and supplemental strategies are required to support vaccine safety programs, including active screening for targeted conditions of interest (e.g., hospitalization), monitoring of new data sources and real-time methodologies to detect changes in vaccine safety data.

• Global collaboration is increasingly required to address challenges in active adverse events following immunization surveillance, particularly for rare serious adverse events.

Notes