Top row. Yearly incidence of HZ (average in dark green, 95% CI in light green),of natural HZ – i.e., by HZ cases occurring among unvaccinated individuals that have experienced natural varicella – (average in red,95% CI in orange) and of HZ caused by the vaccine strain (average in blue, 95% CI in light blue) per 1,000 individuals as obtained by adopting the parallel fit approach and by simulating the two-dose scenario, which assumes the administration of a first dose to 1 year-old individuals (90% coverage) and a second dose to 5 years-old individuals (80% coverage), in Finland (a) in Italy (b) and in the UK (c). Results are based on 1,000 model realizations.