Varicella vaccination programs do not seem to shift the age of disease to older age groups

The article recently published in Pediatrics by Baxter et al. shows the results of the impact of varicella vaccination on the epidemiology of the disease in the United States from 1995 to 2009 (1). The aim of the study was to assess the impact of vaccination on the incidence and severity of varicella both in children and adult population by performing five cross-sectional studies in 1994 (prevaccine), 1999, 2003, 2006 and 2009, in Kaiser Permanente of Northern California