Fig. 1.

(A) Simulated scenario of epidemic diffusion in population showing the illustrated demographic structure. Weekly new infected individuals and cumulative vaccinated ones are illustrated for several age classes. In this simulation, we have assumed that the propensity of infected people to vaccination is equal to zero within 5 months from positive diagnosis and then it increases according to a linear law for the successive 6 months. (B) Estimations of RRR calculated according to Eq. (1) (biased vales) and by means of Eq. (2) (corrected) for several age classes. Should be noted as, for some age class, the RRR estimates significantly decay after the first wave, whereas the corrected estimation is constant and equal to the true value (0.8). (C) Weekly incidence values detected during the simulated epidemic outbreak (week October 4–10, 2021), calculated without excluding recovered unvaccinated individuals from unvaccinated population and (D) by excluding them. Should be noted as, for age classes exhibiting highest vaccination ratios, the uncorrected incidence values for unvaccinated individuals approach that of vaccinated ones. Namely, in the age class of over 80, these assume the same value.