A simple susceptible–infectious–removed epidemic model for smallpox, with birth and death rates based on historical data, produces oscillatory dynamics with remarkably accurate periodicity. Stochastic
†N denotes the number of respondents to the question. +child under 18. #population 25 years and over. *p<0.05; *** p<0.001 based on Chi Squared test (for discrete variables) and t-test (for continuous
