Navarra has obtained an overall reduction in the incidence of varicella of 97% from 2006 to 2012. This has been pointed out by Dr. Manuel García Cenoz, in a thesis presented at the School of Medicine of the University of Navarra.

The study by this Pamplona native shows that "in 2006, in the Autonomous Community of Navarre, when children were not yet vaccinated in infancy, the incidence was 804 cases per 100,000 inhabitants, while in 2012, six years after its inclusion in the vaccination schedule, it had decreased to 21 cases per 100,000 inhabitants". 

In the adult population, a reduction of more than 90% has also been observed in issue of chickenpox cases, so"we cannot speak of a displacement of the disease from children to adults".

According to the expert, the results of Navarra, as well as those of other countries, show that "the effectiveness of vaccination is very high". In this sense, he is of the opinion that "there is no epidemiological reason for not including the varicella vaccine in the vaccination schedules of the rest of the national territory".

Navarra and the Autonomous Cities of Ceuta and Melilla are the only places in Spain that have incorporated the varicella vaccine into the children's vaccination schedule. In the case of the Autonomous Community of Navarre, two doses are administered, one at 15 months and the other at 3 years of age. In the rest of the communities, only those who have not had the disease are vaccinated in adolescence.