Adverse events following immunization: Findings from 2017/2018 measles vaccination campaign, Nigeria AEFI reporting in 2017/2018 measles vaccination campaign

Introduction: An Adverse event following immunization (AEFI) is an untoward medical occurrence following immunization and which may not have a necessary causal relationship with the usage of a vaccine. The World Health Organization categories AEFI into two; serious and non-serious. An AEFI is considered serious if it is life-threatening, requires inpatient hospitalization or results in death. The measles vaccine is safe and effective however because it is a live-attenuated injectable vaccine it is more prone to AEFI as compared to non-injectable vaccines when given in large numbers over a short period as is the nature of measles mass vaccination campaigns (MVC). This article describes Nigeria's experience on AEFI reporting during the 2017/2018 Measles vaccination campaign (MVC). Methods: We reviewed various materials which included the Open Data Kit (ODK) which is an open source smartphone-based data collecting tool, operations room reports, measles campaign tally sheets, AEFI line listing forms, the post measles campaign coverage survey report and the report of the AEFI national expert committee review of the 2017/2018 Nigeria measles MVC. Results: A total of 6,214 suspected cases of AEFI were line listed from all 36 states and the Federal Capital Territory(FCT) during the 2017/2018 MVC with Fever(38%) and pain at injection site the (30%)most common reports. Overall, 99.7% AEFIs were reported to be non-serious AEFIs, with almost all cases resolved fully with no long-term sequalae. The national incidence of suspected AEFI per 100,000 population was 16.3 with subnational incidence highest in Kebbi state (101.3/100,000) and lowest in Bayelsa state (0.8/100,000). Conclusion: Adequate AEFI reporting, Investigation and management remains important in managing the risk of a disruption of mass campaigns. The deployment of supervisors during campaign may play an important role in improving the identification and reporting of suspected AEFI. Further inquiries about AEFIs during the post campaign coverage evaluation also played a role in improving AEFI reporting and documentation. The real-time, on the spot, follow up by the national operations team helped with decision making and intervention including AEFI investigations and assessments.