2009•PubMedRequires access
[Safety and efficacy of varicella vaccine in healthy children--one year follow-up].
Teresa Jackowska, January Dziadek, R Wasilewski, M Wasik
Open publisher page 2 citations
Abstract
BACKGROUND AND AIMS: to assess the safety and efficacy of varicella virus vaccine after administration of one dose. MATERIAL AND METHODS: 106 healthy children (59 girls, 47 boys), with no history of varicella, were vaccinated between March and April 2004. The subjects were aged 9 months to 12 years (median 47 months). Antibody concentrations were determined twice: after 46 days (test 1) and after 13 months (test 2). The concentration of IgG-antibody against VZV was measured using the ELISA IgG Test kit (Genzyme Virotech, Germany). RESULTS: no local and/or general symptoms were observed after vaccination. Effectiveness of vaccination was 98.1%. Two vaccinated children with borderline values (antibody concentrations were 9-11 VE) developed a mild form of varicella 13 months after vaccination. Protective levels of antibody concentrations were found in 95 out of 106 children (89.6%) 46 days after vaccination and in 72 out of 104 children (69.2%) 13 months after vaccination. The mean antibody concentration 46 days after vaccination (test 1) was 21.3VE (6.7-43.8 VE), and 13 months after vaccination (test 2) was 17.2VE (4.9-38.4) i.e. significantly lower (p<0.001). In both tests no significant statistical differences were noted between the post-vaccination concentrations in girls (VE1-20.6 and VE2-22.2) and boys ( VE2-17.3 and VE2-17.0). Neither the subjects' age nor sex at the time of vaccination correlated with the decreased antibody concentrations 13 months after vaccination. In 27.4% of children statistically significant lowering of antibody concentration was detected 13 months after vaccination (lp < 0.0001). CONCLUSIONS: the varicella vaccine (Varilrix) was found to be safe and its effectiveness was 98.1% after 13 months. Only in 2 children mild clinical sings of varicella occurred. However, because of a statistically significant lowering of antibody concentration 13 months after the vaccination, a two dose regimen of varicella vaccination should be recommended.