Statistical studies in immunity : smallpox and vaccination / by John Brownlee.

  • Brownlee, John, 1868-1927.
Date:
1905
Catalogue details

Licence: In copyright

Credit: Statistical studies in immunity : smallpox and vaccination / by John Brownlee. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    690 were under the age of ten years; between 1870 and 1883 out of 2169 like persons 1197 were under the age of ten years. In both of these sets of statistics the distribution of the numbers from birth till ten years is fairly uniform. So that it may be taken for granted that towards the end of last century among persons over twenty years of age who had had smallpox previously one half was the greate.st proportion of these who had the attack during the first ten years of life. In the accompanying table I have collected the details of fifty-one cases TABLE XV. Table of Second Attack of Smallpox. Age at Second Attack. O c3 <1 c3 O bO 0 0 0 0 0 0 1 1 So 1 7 1 1 1 1 1 1 00 1 1 Totals i 0 0 0 0 0 So 0— 5 4 5 2 4 4 1 2 2 1 1 2 1 1 30 5—10 4 — 1 — — 2 1 — 1 — — — — 9 10—15 — — 1 1 2 — 1 1 — — .— — — — 6 15—20 — — 20—25 25—30 40—45 — — 1 — 1 1 — 1 i — — i — — 3 2 ’ 1 Totals 4 9 3 7 6 5 6 1 2 3 1 — 1 51 where persons have had a second atta,ck of smallpox between the years 1887 and 1902, and of these fifty-one it is seen at once that thirty suffered from their first attack of smallpox below the age of five years, nine between the age of five and ten years, leaving a total of only twelve who had their first attack of smallpox above this age. This would seem to show that the protection afforded by an attack of smallpox in childhood is much less complete than that afforded by an attack after ten years. A study of the figures in the table seems to show that this is not due simply to the natural lessening in numbers which occurs in the population at each age period from childhood onwards. A certain amount of support is lent by this to the suggestion advanced earlier in this paper that vaccination performed in early adult life afforded a longer period of protection than when performed in infancy, and in both instances it may be surmised that as the natural susceptibility to smallpox increases from birth onwards till about twelve years there may be a greater loss of acquired immunity daring the same period of life than is likely to occur when the natural protection against smallpox has become more definitely established. With regard to the protection which an attack of smallpox provides against death even less can be said. Of these fifty- one cases seven died. Five of these deaths, however, occurred in one epidemic out of twenty-three cases, and, although one of these five died from apoplexy, yet even four deaths out of twenty-three cases represents a mortality so much in