“…2 Individuals who contracted the infection and recovered; vaccinated individuals are 15 for Puglia region dimensionless 3.8 Latent period weeks 2 (CDC, 2007;Stapleton and Lemon, 1994) Infectious period weeks 3 (CDC, 2007;Stapleton and Lemon, 1994) Decay of survival of HAV weeks −1 0.0833 Abad et al, 1994;Biziagos et al, 1988;Mbithi et al, 1991) in the environment Probability of becoming symptomatic for individuals aged 0-6 percentage 4 (Fiore, 2004;Stapleton and Lemon, 1994) for individuals aged 7-16 percentage 16 (Fiore, 2004;Stapleton and Lemon, 1994) for individuals older than 16 percentage 80 (Fiore, 2004;Stapleton and Lemon, 1994) Vaccine efficacy percentage 98 (Averhoff et al, 2001) by the model is 65.8% in Campania, and 73.8% in Puglia (see Table 2 and 3). These estimates comply with the seroprevalence data reported in (Ansaldi et al, 2008), where an average value of 67.7% is reported for Southern Italy.…”