Parameter combinations for the 10 best-fit simulations for the northeastern U.S. as validated with New York state P&I mortality data.

3000 simulations were performed at each site with the parameters L (mean duration of immunity), D (mean infectious period), φ (vitamin D scaling), and R0* (the basic reproduction number number if γi,t = 1) randomly chosen from within specified ranges. Parameters λ (inflection point) and η (inflection point slope) were fixed at and . Best-fit simulations were selected based on RMS error after scaling the 31-year mean daily infection number to the 31-year mean observed daily excess P&I mortality rate.