[Overdose of yellow fever vaccine in the Southern region of Brazil].

INTRODUCTION Yellow fever is a preventable disease when using a safe, effective vaccine. METHODS A prospective clinical follow-up of 49 people who received an overdose of the wrong vaccine against yellow fever during the 2009 outbreak in a rural area of the Vale do Rio Pardo, State of Rio Grande do Sul. RESULTS During 45 days of clinical follow-up, only 1 (2.1%) case presented manifestations of a possible acute viscerotropism as an adverse postvaccination event. CONCLUSIONS In the group of people monitored following an overdose of anti-yellow fever vaccine, observation confirmed almost total absence of adverse events.