Active surveillance for adverse events following immunization

Area of Science:

• Vaccinology
• Public Health Surveillance
• Pharmacovigilance

Background:

• Post-licensure surveillance of adverse events following immunization (AEFI) is essential for identifying rare safety signals missed in clinical trials.
• Traditional passive surveillance relies on spontaneous reporting, which has limitations in detecting all potential safety concerns.

Purpose of the Study:

• To highlight the necessity of comprehensive AEFI surveillance for vaccine safety.
• To discuss the evolution from passive to active surveillance strategies and the integration of new data sources.
• To emphasize the importance of causality assessment and global collaboration in vaccine safety monitoring.

Main Methods:

• Review of traditional passive surveillance systems.
• Incorporation of active surveillance strategies, including screening for targeted conditions.
• Monitoring of novel data sources and real-time methodologies for AEFI detection.
• Discussion on improved causality assessment techniques.
• Development of frameworks for low- and middle-income countries.

Main Results:

• Active surveillance and supplemental strategies enhance the detection of potential serious adverse events.
• Real-time monitoring and new data sources allow for timely identification of safety trends.
• Improved causality assessment is critical for distinguishing true adverse events from coincidental occurrences.
• Progress has been made in establishing vaccine safety networks, particularly in resource-limited settings.

Conclusions:

• Enhanced AEFI surveillance systems are vital for ensuring vaccine safety.
• A multi-faceted approach combining passive and active surveillance, robust causality assessment, and global collaboration is necessary.
• Strengthening local and global vaccine safety networks is key to protecting public health.