The dynamics of smallpox epidemics in Britain, 1550-1800

The cycle of smallpox epidemics during the 17th and 18th centuries, calculated using the time-series analysis technique, was two years in London, England, and five years in the rural town of Penrith, England. The 'periodicity' of the epidemics appear to relate directly to the cycles of malnutrition and hence the population's susceptibility to the disease.