RESUMO
Varicela Biken [Live varicella Biken vaccine (strain Oka)] is an effective and safe vaccine for the prevention of varicella infection. Although the recommended schedule in all age groups (children, adolescents and adults) is a single dose, physicians in some countries follow the 2007 recommendation of the US Advisory Committee on Immunization Practices (ACIP) which recommends "implementation of a routine 2-dose varicella vaccination program for children, with the first dose administered at age 12--15 months and the second dose at age 4--6 years." ( 1) Therefore, cases can arise when two doses of Varicela Biken are given even though the ACIP guidelines are a response to the US epidemiological situation and for US licensed products based on the Oka/Merck and the Oka-RIT strains (Varicela Biken is not registered in US). The aim of this study is to ascertain the safety of a second dose of Varicela Biken in children who have been previously vaccinated with the same vaccine. In this study, children, 4-6 years of age who had been previously vaccinated with Varicela Biken, received a single 0.5 mL dose of live attenuated varicella virus vaccine containing at least 1000 Plaque Forming Units (PFU) attenuated live Varicella-zoster virus (Oka strain). Participants were monitored for 30 minutes after vaccination. Predefined injection site and systemic reactions were solicited during the subsequent seven days. Unsolicited injection site reactions and unsolicited systemic events were collected throughout the study. Any serious adverse events occurring throughout the study were reported to the sponsor's pharmacovigilance department. One hundred and twenty two children were recruited and all provided safety data. There were no immediate adverse events or injection site reactions. Forty three percent of participants reported injection site reactions and 22.1% reported systemic reactions on solicitation during the seven days after vaccination. During the 30 day monitoring period, 43 participants reported a total of 66 adverse events. Seven participants reported a total of eight unsolicited events that were assessed as related to the vaccine or where the relationship to vaccination was unknown. Five of these eight events were injection site reactions and all were mild, systemic reactions included mild rash (1 case) and fever (2 cases). There was a single serious adverse event that was not related to the study medication (subject was a passenger in a motor vehicle accident). A second dose of Varicela Biken was well tolerated and showed no significant safety issues in this population of previously vaccinated children.
Assuntos
Vacina contra Varicela/efeitos adversos , Imunização Secundária/efeitos adversos , Imunização Secundária/métodos , Vacinação/efeitos adversos , Vacinação/métodos , Argentina , Vacina contra Varicela/administração & dosagem , Vacina contra Varicela/imunologia , Criança , Pré-Escolar , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Exantema/induzido quimicamente , Febre/induzido quimicamente , Humanos , Masculino , Dermatopatias/induzido quimicamente , Dermatopatias/patologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologiaRESUMO
This study evaluated the seroprevalence of poliovirus types 1, 2 and 3 antibodies and vaccination coverage in 780 subjects aged between 7 months and 39 years in Montevideo, Uruguay, where oral polio vaccine (OPV) is used. Antibody titers were measured and seroprotection rates and geometric mean titers (GMTs) were compared among four age groups. Vaccination histories were recorded from documents and interviews. Seroprotection rates ranged from 72% to 95% in children aged 7-23 months, 31-77% in 2-9-year olds, 14-45% in 10-19-year olds and 20-59.5% in 20-39-year olds. Seroprotection decreased significantly with increasing age (p<0.05). Polio vaccination coverage was >90% for the two youngest age groups. These results could help guide public policy decisions regarding polio vaccination, and support the use of inactivated polio vaccine following cessation of OPV.