Determinants of varicella breakthrough: results of a 2012 case control study.

Abstract

This study aims to evaluate the determinants of breakthrough infection after one dose of varicella vaccine. We designed a retrospective case-control study. Breakthrough cases were children, aged 1-15, who presented varicella symptoms ≥ 42 days after the first dose of varicella vaccine (breakthrough). Controls were children, aged 1-15 years, who attended the same class (in a school or in a kindergarten) than the cases in the year of the breakthrough onset; they received a dose of varicella vaccine ≥ 42 days before the case rash onset and they did not develop varicella symptoms. We enrolled 45 cases and 135 controls. 40% of cases (n = 18; 95% CI = 25.4-54.6) presented at least one risk factor; this proportion was 39.2% (95% CI = 30.9-47.6) among the controls (chi-square = 0.0078; P = 0.93). Time between vaccination and virus exposure was longer among cases. Logistic regression showed that breakthrough disease was associated with duration of time from vaccination.

• Authors: Silvio Tafuri, Rocco Guerra, Maria Giovanna Cappelli, Domenico Martinelli, Rosa Prato, Cinzia Germinario
• Journal: Human vaccines & immunotherapeutics (Hum Vaccin Immunother) Vol. 10 Issue 3 Pg. 667-70 ( 2014) ISSN: 2164-554X [Electronic] United States
• PMID: 24398423 (Publication Type: Journal Article)

Topics

• Adolescent
• Case-Control Studies
• Chickenpox (epidemiology, immunology, prevention & control)
• Child
• Child, Preschool
• Female
• Humans
• Infant
• Italy (epidemiology)
• Male
• Retrospective Studies
• Risk Factors
• Time Factors