An Estimate of the True Value of Vaccination as a Security Against Small Pox

by T. M. Greenhow

If we extend this calculation to the whole of Great Britain and Ireland, assuming that the ratio in the diminution of deaths has been the same over the united kingdom as within the London bills of mortality—(and there are various good reasons for believing that it has been greater)—we cannot but be struck with the immense saving of human life which has already taken place. Sir Gilbert Blane and Dr. Letsom separately calculated the annual loss of lives from Small Pox, in Great Britain and Ireland, during the last thirty years of the eighteenth century.—One of these eminent physicians estimated them at 34,260, and the other at 36,000 (Moore’s History of Small Pox, p. 300): For our present purpose, we will take a medium number, as being probably nearest to the truth. Assuming then, that the number of deaths from Small Pox, in the United Kingdom, during each of the twenty-five years which preceded the introduction of Vaccination, amounted to 35,000, the amount, during the whole of that period, must have been 875,000. But if the diminution on the whole of this number has been equal to that which is proved to have taken place within the London bills of mortality, during the last twenty-five years, it must have been reduced to 481,644 only, and an actual saving of the lives of 393,356 individuals must have been accomplished.

These calculations agree pretty nearly with estimates published in the year 1820, by Sir Gilbert Blane, founded on similar documents. His calculations extend to the parishes not included within the bills of mortality, and he comes to the following conclusion on the subject:—“It appears, therefore, that even under the very imperfect practice of Vaccination, which has taken place in the metropolis, 23,134 lives have been saved in the last fifteen years, according to the best computation that the data afford”—(Sir G. Blane on Vaccination, p. 7). But however remarkable and satisfactory this immense saving of human life, in the country where Vaccination originated, may appear, as an unanswerable evidence of its efficacy, the result has been still more decisive in many foreign countries, where it has been much more generally employed. In proof of this, I shall again quote the very valuable little work of Sir Gilbert Blane, (which, by the way, I should strongly recommend to the attention of the public, as containing much valuable matter and sound argument within a very small compass). He states, (p. 7-8) “In the summer of 1811, the author was called to visit, professionally, Don Francisco de Salazar, who had arrived a few days before in London, on his route from Lima to Cadiz, as a Deputy to the Spanish Cortes. He informed him, that Vaccination had been practised with so much energy and success in Lima, that for the last twelve months there had occurred not only no death from, but no case of, Small Pox: that the new born children, of all ranks, are carried as regularly to the Vaccinating house as to the font of baptism; that the Small Pox is entirely extinguished all over Peru; nearly so in Chili; and that there has been no compulsory interference on the part of the government to promote Vaccination.”

Sir Gilbert goes on to say, that “it is now matter of irrefragable historical evidence, that Vaccination possesses powers adequate to the great end proposed by its meritorious discoverer, in his first promulgation of it in 1798, namely, the total extirpation of Small Pox. The first proof of this was at Vienna, where, in 1804, no cases occurred, except two strangers, who came into the city with the disease upon them. In 1805 there did not occur a single death from it in Copenhagen. Dr. Sacco, the indefatigable superintendent of Vaccination in Lombardy, stated in his annual report, 3d January, 1808, that the Small Pox had entirely disappeared in all the large towns in that country; and that in the great city of Milan it had not appeared for several years. Dr. Odier of Geneva, so favourably known for his high professional, scientific, and literary acquirements, testifies that, after a vigorous perseverance in Vaccination for six years, the Small Pox had disappeared in that city and the whole surrounding district; and that, when casually introduced by strangers, it did not spread, the inhabitants not being susceptible. The central committee in Paris testify, in their report of 1809, that the Small Pox had been extinguished at Lyons and other districts of France.”

“These are selected as some of the earliest and most remarkable proofs of the extirpating power. But it is demonstrable, that if at the first moment of this singular discovery, at any moment since, at the present or any future moment, mankind were sufficiently wise and decided to vaccinate the whole of the human species, who have not yet gone through the Small Pox, from that moment would this most loathsome and afflicting of all the scourges of humanity, be instantaneously and for ever banished from the earth.” (p. 8).

These, and such as these, then are the great, the undeniable facts, which must, I think, carry irresistible conviction to every reflecting and unprejudiced mind respecting the true value of Vaccination. And it is these facts which furnish us with an answer to the second question proposed—What influence has Vaccination exerted over the destructive consequences of Small Pox? which it must be truly gratifying to every philanthropic mind to contemplate. In the course of twenty-five years, in our own country, where it has been very partially employed, it has actually been the means of saving a number of lives, amounting to 393,356; and if it be true, as supposed by Sir Gilbert Blane, that Small Pox induced “blindness, deformity, scrofula, or broken constitutions,” in as many who recovered from the disease as died in consequence of it, then have an equal number been saved from these dreadful calamities. But abroad, where it has been more generally employed, Vaccination has, in many places, actually exterminated the Small Pox altogether.

From what has already been said, it will be evident, that Vaccination has produced these very beneficial consequences in two ways. 1. By superseding an efficient cause of the spread of infection, namely, the practice of inoculation for Small Pox. And 2. by essentially interfering with the effect of the infectious virus.

The increased number of deaths, which took place during the period when inoculation for Small Pox was generally employed, is sufficient to prove the influence of Vaccination to have been considerable in the former way; but a formal application having been made to me to inoculate a child for Small Pox, since I commenced these remarks, I think it right to call the attention of the public more decidedly to the pernicious tendencies of the practice.

The attention of the medical profession, and of the public generally, was soon excited by the increasing number of deaths after the introduction of inoculation, and exertions were made to check it, particularly by the establishment of the Small Pox Hospital. This, no doubt, had some effect, by separating a part at least of those to whom Small Pox was artificially communicated from the rest of the community; but the event proved that this was by no means an adequate defence against the factitious causes of infection, which were daily called into action. The Small Pox Hospital still exists, and it is a very remarkable fact, that, for several years after the discovery of Vaccination, out-patients continued to be inoculated at that institution. This, no doubt, contributed to prevent the proportion of deaths from Small Pox in London from diminishing so rapidly as would otherwise have been the case, and as has been the case, since this “unaccountable infatuation,” as Sir Gilbert Blane very justly calls it, has been discontinued. But, as the same eminent physician properly remarks (p. 6), “it was in the rural population that the effect of inoculation in diffusing Small Pox was chiefly felt. In this situation, there is much less intercourse of persons with each other than in towns, so that not only many individuals escaped, from their not being exposed to infection during their whole lives, but whole districts were known to have been exempt from it for a long series of years before it was universally diffused by inoculation.” We may, therefore conclude, that while the number of deaths from Small Pox, within the bills of mortality, was increased in the proportion exhibited in the tables by means of inoculation, in the country the increased mortality from this cause was in a much greater ratio. This supposition is in a great degree confirmed by the effects occasioned by a renewal of the practice of inoculation, in Norfolk, in the year 1819, as recorded by Mr. Cross, in his History of the Epidemic Small Pox, which at that time prevailed in the city of Norwich and the county of Norfolk. Mr. Cross mentions many instances of the disease being introduced into parishes, in which it did not before exist, by means of inoculation, the contagion afterwards spreading in all directions; and affirms (p. 272), that “thirty-eight surgeons, who from various motives, practised it, lost among those to whom they had thus given the disease, twenty-one patients; fourteen surgeons reported, that fifty-five deaths had been occasioned in the same way within their knowledge; and five other surgeons observed, that they had known several who fell a sacrifice to the practice.” It admits then of the most incontestable proof, and it is a fact, which cannot be too deeply impressed upon the minds of the public, that inoculation for Small Pox is a practice attended with very considerable danger to the individual who passes through it, while to society in general, it has been productive of the most pernicious consequences. Is it too much then to affirm, that it cannot be employed without great moral guilt being incurred both by those who may require its performance, and by the medical practitioner who shall be induced to practise it?

But by far the most important mode in which Vaccination has been productive of the equally astonishing and gratifying consequences, which have been proved to have resulted from it, has been by its essential interference with the effect of the infectious matter of Small Pox, either by entirely preventing the occurrence of that disease, or by stripping it of all its dangerous and formidable characteristics—rendering it, in the comparatively few instances in which it has taken place at all after Vaccination, mild in its attack, and perfectly harmless in its consequences.

It very generally happens, when a discovery is made which promises to exert any considerable influence over the happiness of man, that its capabilities cannot for some time be very accurately defined; and that the effects, which a few years’ experience shall prove it to possess the power of producing, will, at the commencement, be either undervalued or overrated. It would not, perhaps, be difficult to adduce instances of both. And it can scarcely excite surprise, that something like this should have been the case with incomparably the most important discovery of modern times, for such we may truly esteem Vaccination, whether we consider it as a means of preserving life, or of obviating effects, perhaps, even more deplorable than the loss of life itself.