THE NATURALIST.

Otago Witness, Issue 2561, 6 May 1903, Page 64

THE NATURALIST.

Vaccination Does Protect.

We do not claim that vaccination protects throughout life, but that it protects for a number of years, and, if properly performed, on the average for 10 years. There wae a theory that all the materials of our bodies are completely changed e\ery seven years, and that this was the time to which the influence of vaccination was limited. This was merely a guess at the time when the tipsue elements of the bemes were changed. We ha%e no reason to believe now, with larger knowledge, that it has any substantial foundation; whereas the estimate of time we have given is not founded on theory, but on the result of experience in epidemics of emallpox. It ir found that very few of the children who have been vacc'mated in infancy, and are still under tho age of 10 yeais, take the disease, while the numbers increase as the years beyond 10 are reaohed. Revaccination about 12, as practised in Germany, where the primary vaccination is within the first two years, is found to be an effective protection against the disease, for the prevalence of smallpox in Germany has greatly diminished since these precautions were takcai. Enormously is, perhaps, a more adequate word to qualify the change which has taken place there. While r«vaccination was practised in the Prussian army previously, it was only made compuhory on all at school age in 1874. Previous to that time, the statistics show an average death-rate of 79 per million per annum, with a high-water mark, of 85 per million ; wjiereas lince 1874 the average death - rate per million has been 11 ovei the 24 years, with an almost uniform and gradual descent from 36 per million in 1675 to a minimum of one in five millions.

Statistics for the whole German Empire, with a population of 52,000,000, from 1886 to 1889, give an average of 1.7 per million ; while the neighbouring country if Austria, where vaccination is aiot compulsory, for a similar period gives 283 leaths per million of the population. Revaceination of the whole community, so that none, or almost none, escape, is much more efficient than a limited provision, since the "soil," being unfruitful, does not tend to produce the necessary infective material, and so diminishes the risks of those who happen to be imperfectly protected, such £U< the older people who were revaccinat€d 30 or 40 years ago.— Liverpool Mercury.