Varicella prevention in Costa Rica: impact of a one-dose schedule universal vaccination.

To describe the impact following a 1-dose Varicella vaccination schedule introduced in Costa Rica in September 2007. Areas covered: This is a retrospective review using epidemiologic surveillance national databases of varicella cases and hospitalizations, period 2000-2015. We analyzed age-related varicella incidence cases and hospitalization trends before and after the vaccine introduction. Expert commentary: Varicella vaccine coverage among children 16 months age increased from 76% in 2008 to 95% in 2015. During this period Costa Rica reached a 73.8% reduction of Varicella reported cases and 85.9% reduction of hospitalizations in the general population. Among children under 5 years of age, that reduction was 79.1% and 87%, respectively. Varicella complications in hospitalized patients decreased 98%, from n = 53 in 2008 to n = 1 in 2014. After 8-years post implementation of a 1-dose schedule of universal varicella vaccination, a dramatic overall disease reduction in incidence, hospitalizations and complicated cases has been observed in all age groups.