Follow up of severe adverse effects supposedly attributable to vaccination or immunization reported to the Ministry of Public Health between 2010 and 2014

Abstract

Introduction: adverse events supposedly attributable to vaccination or immunization are negative events that follow immunization and may be attributed to it. The study aimed to characterize and follow up severe adverse effects reported to the National Pharmacovigilance System of the Ministry of Public Health during 2010-2014.

Method: a transversal study of the evolution of the individuals affected was performed by means of a telephone survey. Variables used to characterize possible complications were the following: treatment required, time until recovery, type of recovery, disability and death. Behavior upon the following vaccination was also evaluated. Definitions from Brighton Collaboration and the World Health Organization were used to describe the events.

Results: 107 cases of severe events were reported between 2010 and 2014, which corresponded to 79 individuals, 53 of which were analysed. Most of the severe events were associated to neurological disorders, seizures being the most frequent one. None of the patients evidenced sequelae, 48 individuals fully recovered, five presented long-term sequelae. No event resulted in a cause of the death at the time the study was completed.

Conclusions: this is the first study that analyses the evolution of severe adverse effects reported to the National Pharmacovigilance System. It is important to sensitize the health team in terms of notifications and to strengthen the national follow-up protocols based on this experience.