In 1936 a study was made1 of smallpox immunity in 1,053 matriculating college students at Kansas State College. A similar study of 986 students made in September 1937 with additional data on the duration of smallpox immunity and the effect of multiple vaccinations constitutes the basis of this report. Table 1 gives in tabulated form the detailed histories and results on the vaccinated group. This college age group was very largely derived from rural areas and small towns in Kansas.
Of the vaccinated group 74.9 per cent gave a positive history of previous vaccination against smallpox and had a visible scar; 3.3 per cent had not had a previous vaccination but gave a positive history of smallpox; 20.4 per cent had neither been vaccinated nor had smallpox but gave a positive history of chickenpox; 1.2 per cent gave an entirely negative history for previous vaccination against smallpox, smallpox and
LOY DT, HUSBAND MW. DURATION OF SMALLPOX IMMUNITY. JAMA. 1938;111(9):780–781. doi:10.1001/jama.1938.02790350020006