Fig. 2

Impact of ρ on eHCoV dynamics and pHCoV hospitalisation rates. a Mean age at first infection with any eHCoV (black dots) and with a specific strain (red dots) as a function of ρ. The dashed line and shaded area represent respectively the mean and 95% C.I. for the age at first infection with any eHCoV obtained from a pooled estimate [50]. b 5th percentile of the time (measured in years) between consecutive infections by the same strain. Hatches indicate the ρ > 1/R₀ region (for R₀ = 2) where the dynamics are Susceptible-Infected-Susceptible-like (whereas for ρ < 1/R₀ we observe epidemic behaviour). It should be noted that for ρ = 0 reinfection still occurs in our model because of external introductions, which we have assumed for simplicity to ignore pre-existing immunity to reinfection. Nonetheless, reinfection events induced by external introductions represent only a small fraction of all infection events. Epidemiological parameters are set to baseline values