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

by T. M. Greenhow

Such then were the data on which the practice of inoculation for Small Pox was established. But it will be remembered, that on its introduction, and for many years after it had been extensively used, it met with a very warm opposition both from medical men and others, especially from some zealous divines, who stigmatised it as “a diabolical invention of Satan,” and uttered anathemas against all who should practise it. I shall not enter into any examination of the arguments made use of by the opposers of inoculation; some of them have been already alluded to, and their fallacy pointed out. Taken altogether, it is remarkable how nearly they resembled those which have been opposed to the introduction of Vaccination. Now, that distance of time has enabled us to view the facts of the case with coolness, and to reason upon them without prejudice, while we admit the individual security which arose from the practice of inoculation, we must in candour confess its tendency to encrease the general destruction of life from Small Pox, by forming so many new sources of infection. This was the only rational argument against inoculation, but it was certainly one of great force, and the actual encrease of deaths from Small Pox during the prevalence of inoculation, seems to prove that it was never sufficiently considered. The encreased number of deaths from Small Pox in 1723 and 1725, might fairly be imputed to this cause, although it was denied at the time by Dr. Jurin. Mr. Moore (History of Small Pox, p. 243) very satisfactorily replies to Dr. Jurin’s argument in the following extract. “And as in the year 1723 a great increase of the mortality by Small Pox took place in London; Dr. Jurin expressed his opinion that this ought not be imputed to inoculation, as the numbers who had been inoculated did not exceed sixty. This was a very inadequate answer. A single person may bring the plague into a town or into a nation, and be the cause of the destruction of an innumerable multitude. The Small Pox is fully as infectious a disease as the plague; and sixty inoculations were more than sufficient to account for the augmented mortality, and were probably the cause of it.”

If we refer to the tables (No. 1 and 2), we shall find that from the years 1752 to 1798 inclusive (the period during which inoculation was most extensively employed in this country), the average mortality from Small Pox, during periods of five years each, was occasionally so high as one in eight of the whole, and rarely less than one in ten. And that during individual years, it three times (in 1752, 1781, and 1796) amounted to nearly one in five; and in 1772 was little less than one in six. This is surely a fearful encrease on Dr. Jurin’s calculation—“That of all the children that are born, there will some time or other die of Small Pox one in fourteen.” There can be no doubt, however, that this immense encrease of mortality from Small Pox was owing to the extended practice of inoculation; and until this could have been pursued more generally, and with greater precautions, so as at once to diminish the numbers capable of being infected by the inoculated, and the hazard of the latter coming into contact with the unprotected, I am disposed to think this fact was in itself sufficient ground for discontinuing inoculation for Small Pox altogether. Could every child have been subjected to the process of inoculation, before any exposure to the infection of natural Small Pox had taken place, the case would have been widely different: but it can scarcely be considered either just or politic to render one individual secure at the risk of endangering many, or with a certainty of destroying some. It may fairly be concluded, then, that inoculation for Small Pox, as practised for the last fifty years of the eighteenth century, although certainly a great individual good, was, in reality, without a doubt, a most serious general evil.

From what has been hitherto stated, I conceive, we are authorised in assuming the following as facts, which will furnish a satisfactory answer to the first of the questions proposed, What were the destructive consequences of Small Pox previous to the introduction of Vaccination?

1. Small Pox is a disease of so infectious a nature, that few individuals passed through life without suffering from an attack of it.

2. It was attended with so much danger as to occasion the death of one in five or six of those affected by it in the natural way; and previous to the use of inoculation, one in fourteen of the whole number of children born, at one time or other, died of the Small Pox.

3. Of those who recovered, many suffered materially from its effects, not only in the disfigurement of countenance occasioned by it, but frequently in the loss of one or both eyes, or in irreparable injury of their constitutions.

4. After having been once affected by Small Pox, a very considerable proportion of individuals resist entirely a second attack: but still in very many instances a recurrence of the disease is proved to have taken place.

5. Secondary Small Pox is, for the most part, very mild in its symptoms, and of shorter duration than a first attack, insomuch as to have frequently given rise to doubts respecting the real nature of the disease.

6. Secondary attacks of Small Pox have, nevertheless, occasionally proved fatal.

7. When artificially produced by inoculation, the Small Pox is rendered materially milder in its character, so that one in two hundred only of those to whom the disease has been thus communicated, have been found to die in consequence.