OBJECTIVES: Varicella (chickenpox) is one of the most contagious diseases affecting approximately 90% of children before the age of ten, and thus constitutes a considerable health and societal burden. Currently, varicella vaccination is not part of the Danish National Immunization Program (NIP) but has been available for out-of-pocket purchase since 2019. Currently, no data are available on patterns of varicella vaccination uptake in Denmark.

METHODS: This nationwide, population-based study was conducted on 1,320,408 individuals aged 1 to 18 years from 2019-2022. Data on sociodemographic factors for children and their parents were linked to varicella vaccination status. Associations were estimated by crude and adjusted multivariable logistic regression models. We accounted for dependency between siblings by applying a robust standard error estimator, and for trend by including an interaction term between birth year and time in study.

RESULTS: Varicella vaccination coverage rates increased five-fold from 2019 to 2022, with the highest uptake in the youngest age-groups (<10 years). The likelihood of vaccination after adjustment was markedly increased among children of parents with high education (OR: 5.99, 95% CI: 4.50-7.98), and high income (OR: 3.06, 95% CI: 2.77-3.38). Further, children living in capital/metropolitan areas were more likely to be vaccinated.

CONCLUSIONS: Varicella vaccination uptake is higher among families with high socioeconomic status and living in capital/metropolitan areas. It is conceivable that the observed social inequality will persist over time as varicella vaccine uptake rises in the private market. To ensure equitable access to varicella vaccination, the value of including the vaccine in Denmark’s NIP should be evaluated.