It was urged, and proofs were offered in support of the statement, that vaccination did not give the protection asserted, that many vaccinated persons were seized with small-pox, that vacci nation so affected the system as to lay it open to such diseases as consumption, scrofula, &c., and that, with the vaccine matter, the poison of such diseases as syphilis might be and was introduced. The result of these more scientific objections was to rouse the supporters of vacci nation to the fullest and most far-reaching inquiries. Medical colleges and medical men were appealed to in every civilized nation, and as a consequence a body of evidence in favour of vaccination was produced, which to this day stands unassailed and unassailable, fitted to convince every rational mind that vaccination, if properly and universally employed, affords a method of completely stamping out small-pox from the face of the earth. Anyone who chooses to examine the question for himself will find the facts in " Papers Relating to the History and Practice of Vaccination," presented to the British House of Commons, and published in 1857. Some of the most striking facts may be given. It is estimated that in 100 years before the introduction of vaccination, 45 millions of persons died in Europe of small-pox. In Green land, in 1734, two-thirds of the population were swept away by an epidemic. In Iceland, in 1707, it destroyed 18,000 out of a population of about 50,000. In North America one tribe of Indians, numbering 1500 persons, all perished by its ravages excepting only 30. It is esti mated that in the Russian empire alone it had annually two millions of victims. After the introduction of vaccination the death-rate from small-pox fell at once, and diminished just in proportion to the thoroughness and extent of the practice. In Sweden, before its introduc tion, small-pox had annually 2050 victims, after its introduction only 158; in Berlin, for 24 years before its introduction, the deaths from small pox were 3422 annually, for 40 years after its introduction the annual death-rate fell to 176; in London the annual deaths from small-pox before vaccination were 3000 to 5000, after its introduction they were under 340. It is to be remembered that these results were obtained when vaccination was not nearly universal, and that the deaths were chiefly among non-vaoci nated persons.
It appears, ho*ever, quite true that the pro tection from vaccination is not absolute. That is to say, there have been cases where persons properly vaccinated have yet contracted small pox, but in every case the disease was so mild as to cause little risk of death. Such cases are, however, rare. It was abundantly proved that the very large proportion of cases brought for ward, of persons who had contracted small-pox after vaccination, were really cases in which the vaccination had been improperly performed. It was shown that matter, in no sense true vaccine matter, might be used which would produce irritation at the point of insertion and set up inflammatory changes, which ignorant persons might suppose to be the vaccine pocks, but were not so. Such false vaccination could not give protection. While this was proved, it is ad mitted that in a few cases, indeed a very few cases, proper vaccination may not completely protect from small-pox, though it renders the disease extremely mild. But then there are undoubted cases on record where one attack of small-pox itself does not confer complete pro tection from a second. Indeed it would appear that the protective power of efficient vaccina tion is of the same extent as the protective power of a previous attack of small-pox.
The explanation of the protection accorded by small-pox is one that was surmised by Jenner himself. Numerous positive experiments go to show that the pocks of the cow and the small pox of man, as well as (apparently) the pocks of the horse, are due to one and the same poison operating with different degrees of violence on different animals. Thus Mr. Ceely, a surgeon
of Aylesbury, began a series of experiments in 1839, which went to prove that small-pox poison introduced into the body of a cow produced cow-pox. Thus, in one case, he introduced small-pox poison into a stirk. At the place of puncture the cow-pox appeared by the sixth day. From one pock he took matter with which he vaccinated several children, and in the chil dren it produced the appearance of ordinary vac cination pocks. He passed this matter through several generations iu children, and obtained a supply of matter which was used in the Small pox Hospital and Cow pox Institution of Dublin, and gave all the results of ordinary vaccination. Thus small-pox of the human being became cow-pox in the cow, and the matter of the cow-pox, when transferred to the human being, became the vaccination-pox. It thus ap pears that vaccination protects against small-pox because it is, as regards the poison producing it, the same disease, but deprived of its violence and extremely poisonous charadter by previous passage through the cow. Therein lies the reason why vaccination cannot protect more absolutely against smallpox than small-pox itself.
As tending to show how the objection that vaccination does not give complete protection against small-pox is rather an argument against imperfect vaccination, one or two facts may be given in the form of a table. The table is based on the observation of 5000 cases of small-pox received in the Small-pox Hospital of London. It states the death-rate among different classes of patients; (I) the unvaccinated, and (2) the vaccinated. But the vaccinated have been divided into different sets according to the number of vaccination marks or scars found on their persons.
Of unvaccinated, there died ... 35 out of every 100 Of those said to be vaccinated but having no mark, there died} 23 „ „ 100 Of vaccinated— Showing 1 mark, there died nearly 8 out of every 100 „ 2 marks, „ 5 71 91 100 „ 2 „ „ 100 19 4 I/ 1 ,, 200 These figures are confirmed in the experience of other hospitals. It appears thus that the more thorough the vaccination the more complete the protection, and that that amount of vacci nation is safest which leaves four well-marked scars.
It has been shown that the protective power of vaccination diminishes after the lapse of yeara That objection is easily met. It is only neces sary to have the vaccination repeated whenever necessary. (See RE-VACCINATION, p. 530.) The gravest objection that has been urged against the practice is that vaccination has, in many cases, been the direct cause of serious disease. It is quite true that carelessness and want of cleanliness on the part of parents to wards their vaccinated children may result in serious inflammation, erysipelas (rose), &c., of the vaccinated arm. But filthiness will render a pin-scratch a serious affair, and it is mon strous to suppose that parental neglect is to be an objection to a method for protecting the lives, not of one hero and there, but of the whole community from a disgusting and fatal disease. Unfortunately there can be no doubt that syphilis has been communicated by vac cination. It has been shown, however, that pure vaccine matter taken from a syphilitic child cannot communicate syphilis to another child. It is only when the vaccine matter is mixed with the blood of the diseased child that risk arises. There are, therefore, two safe guards against such a danger, one is the evideuce to the eye that the matter about to be used has no trace of mixture with blood, the other is due care in the selection of a healthy child from whom the matter is to be obtained. In short, care on the part of both parent and vaccinator are two absolute safeguards against the possibility of any danger arising from the practice.