Varicella Vaccination Coverage and Possible Factors Influencing Parental Vaccination Decisions in Munich Area 2009-2011 after Introduction of Routine Varicella Vaccination

Abstract

Background and Objective: Germany introduced routine varicella vaccination for all infants aged 11-14 months in 2004; since 2009, a second dose was recommended for toddlers aged 15-23 months. In Bavaria, vaccination with combined MMRV vaccine has been routinely reimbursed since the introduction of the 2-dose vaccination schedule. We investigated varicella vaccination coverage and factors associated with parental acceptance of varicella vaccination in the area of Munich from 2009 to 2011, within the frame of the 'Bavarian Varicella Surveillance Project' (2006-2011). Method: Annual cross-sectional parent survey of random samples of 600 children aged 18-36 months in Munich on the child's vaccination status for varicella and measles, socio-demographic data and parental attitude towards varicella vaccination. Results: During 2009-2011, the first dose varicella vaccination (VV) coverage increased from 53% (2009) to 68% (2011) while the second dose VV increased from 29% (2009) to 59% (2011). First-dose measles vaccination coverage was 88-91% (2009-2011). In 2009, 51% of all vaccinated children received the combined MMRV vaccine as first dose; in 2011, 94% (p<0.001). In 2009, 27% of all parents considered varicella vaccination as superfluous. This percentage had decreased to 15% by 2011. Recommendation of varicella vaccination by the physician was the most important explanatory factor and was significantly associated with parental acceptance of varicella vaccination in 2009 to 2011 (adjusted OR 11.5; 95%CI 3.6-36.3 (2009), 26.7; 95%CI 5.4-132.2 (2010) and 12.7; 95%CI 3.9-41.4 (2011)). Conclusions: From 2009 to 2011, first dose VV coverage further increased by approximately 15% up to 68%, corresponding with the increased use of MMRV. Although parental acceptance had increased, first dose coverage for varicella was still considerably lower than coverage for measles in 2011. Physician's recommendation of VV was the only independent factor significantly associated with parental acceptance in all study years. A further increase in varicella vaccination coverage is necessary in order to avoid potential negative effects such as an increase in the mean age of children getting infected with varicella. Therefore, information campaigns for both parents and physicians are urgently needed.