Use of electronic immunization registry in the surveillance of adverse events following immunization.

Vinícius Leati De Rossi Ferreira,Ângela Aparecida Costa,Marta Inenami,Eliseu Alves Waldman,Edmar Martineli,Laura Cunha Rodrigues,Márcia De Cantuária Tauil,Mariana Bernardes Barros,Ana Paula Sayuri Sato

doi:10.11606/s1518-8787.2018052000295

Abstract

ABSTRACTOBJECTIVETo describe adverse events following vaccination (AEFV) of children under two years old and analyze trend of this events from 2000 to 2013, in the city of Araraquara (SP), Brazil.METHODSThis is a descriptive study conducted with data of the passive surveillance system of AEFV that is available in the electronic immunization registry (EIR) of the computerized medical record of the municipal health service (Juarez System). The study variables were: age, gender, vaccine, dose, clinical manifestations and hospitalization. We estimated rates using AEFV as numerator and administered doses of vaccines as denominator. The surveillance sensitivity was estimated by applying the method proposed by the Centers for Disease Control and Prevention. We used Prais-Winsten regression with a significance level of 5.0%.RESULTSThe average annual rate of AEFV was 11.3/10,000 administered doses, however without a trend in the study period (p=0.491). Most cases occurred after the first dose (41.7%) and among children under one year of age (72.6%). Vaccines with pertussis component, yellow fever and measles-mumps-rubella were the most reactogenic. We highlighted the rates of hypotonic-hyporesponsive episodes and convulsion that were 4.1/10,000 and 1.5/10,000 doses of vaccines with pertussis component, respectively, most frequently in the first dose; 60,0% of cases presented symptoms in the first 24 hours after vaccination, however, 18.6% showed after 96 hours. The sensitivity of surveillance was 71.9% and 78.9% for hypotonic-hyporesponsive episodes and convulsion, respectively.CONCLUSIONSThe EIR-based AEFV surveillance system proved to be useful and highly sensitive to describe the safety profile of vaccines in a medium-sized city. It was also shown that the significant increase of the vaccines included in the basic vaccination schedule in childhood in the last decade did not alter the high safety standard of the National Immunization Program.

Highlights

Vaccination actions with the National Immunization Program (NIP) have contributed to a significant reduction in the burden of vaccine-preventable diseases in Brazil[8]
It was shown that the significant increase of the vaccines included in the basic vaccination schedule in childhood in the last decade did not alter the high safety standard of the National Immunization Program
In 2003, the World Health Organization (WHO) established a comprehensive surveillance system to ensure the safety of vaccines administered in national immunization programs[22]

Summary

Introduction

Vaccination actions with the National Immunization Program (NIP) have contributed to a significant reduction in the burden of vaccine-preventable diseases in Brazil[8]. As the risk perception of these diseases decreases as a result of successful immunization programs, the perceived risk of vaccine-preventable diseases (adverse events following immunization – AEFI) may increase, decreasing adherence to vaccination and, creating conditions for resurgence of diseases already controlled[4]. In Brazil, the state of São Paulo evaluates the AEFI since 1984, an initiative that became national in 1998 with the implementation of the passive surveillance system of AEFI by the NIP. The Information System of the NIP (IS-NIP) is in the process of being implemented in Brazil, which is a database on vaccination that aggregates the Information System of AEFI (IS-AEFI), with online record on the notification, investigation, management, and final classification of these events The surveillance of AEFI is aimed at correcting programmatic errors, identifying the existence of specific more reactive batches, investigating rare or unknown events, and studying associated factors to maintain the public confidence in the immunization program[22].

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