Varicela y Herpes Zóster en España, 1998-2012

In Spain, varicella vaccination for susceptible adolescents was introduced in the routine immunization schedule in 2005. Vaccination courses have been readily available at Spanish pharmacy counters since 2004. Between 2006 and 2008, Navarra, Madrid, Ceuta and Melilla –four Spanish regions- also included children in their routine immunization program. Different immunization coverage was detected in the remaining Spanish regions where varicella vaccination was randomly extended to children beyond official guidelines. Two factors were studied in order to assess the impact of varicella vaccination against both varicella and Herpes Zoster and to derive their seriousness and epidemiology. Firstly, the results of pre-vaccination (1998-2004) and post-vaccination (2006-2012) periods were analyzed. And secondly, Spanish regions that included childhood vaccination in their programs were compared to those that did not. Regions were systematic childhood vaccination was carried out saw a significant reduction of varicella cases (16%) and chickenpox related hospitalizations (64%). Other regions only showed a 9% and 43% reduction. Fewer Herpes Zoster related hospitalizations were recorded during the post-vaccination period. There was however, an increase in hospital admissions in patients over 64. The increase in senior HZ patients was even more significant in those regions were children varicella cases decreased the most. WHO recently outlined that varicella epidemiological pattern is subject to change in areas were vaccination coverage is below 80%. Spanish regions that did not follow the official recommendations are thus prone to experience these alterations. Furthermore, it is likely that these regions will see a surge of children reaching 12 being still susceptible to chickenpox. All susceptible adolescents must receive two vaccine doses before adulthood. Varicella and herpes zoster surveillance must be maintained and improved in order to monitor any significant change in their epidemiology.