Fig. 1

Incidence rates. A Incidence rates by age in the non-vaccinated population, averaged over the period from September 2011 to August 2018 (cases per 100,000 person-years, \({\mathrm{e}}^{{\uprho }_{\mathrm{a}}}\) in the model; m: months, y: years). B Are yearly incidence rates ratios (\({\mathrm{e}}^{{\upbeta }_{\mathrm{t}}}\) in the model) in the non-vaccinated population (for the 4 years before immunization, i.e., from 2011 through 2015, this is the whole population), calculated relative to the 2011–2018 average (used as a baseline, fixed to 1, shown as a dashed horizontal line). C Incidence rate ratios in vaccinated relative to non-vaccinated subjects, by number of doses received (\({e}^{{\theta }_{d}}\) in the model). Bars report 95% credible intervals around point estimates. P values: ***P < 0.001