Part 73

To sum up, then, vaccination almost invariably protects against small-pox for the time being; generally for a long term of years; sometimes for a lifetime. Often the protection is absolute; as a rule, it is very nearly so; in rare instances it is trifling. In general terms, it may be said that it is scarcely less protective than variolous infection itself, for death from a second attack of small-pox is by no means rare. Here the question comes up: Is vaccination less protective, either in degree or in duration of effect, than it was at the time of its adoption? Given a typical vaccinia, we may unhesitatingly answer, No; but do we now so invariably produce the disease in all its essential features as was done in Jenner's time? Yes, provided we use proper virus and employ as much care as was taken by the older physicians, who, trained to the practice of variolation (the inoculation par excellence of bygone days), did their work with a gusto now seldom witnessed. But there was a time, now happily at an end, when it was not easy to obtain thoroughly good virus, and when, therefore, the result was apt to vary materially from the standard. This may be conceded without entering upon the vexed question of the general deterioration of the Jennerian stock of vaccine.

Besides immunity from small-pox, there are one or two sequelæ of vaccinia that deserve mention before we proceed to consider what it is better to class as complications. In the first place, vaccination has been supposed to confer temporary protection against whooping cough. The writer is not aware, however, of any precise data going to prove either the truth or the falsity of this supposition.

Secondly, by virtue probably of the inflammation that attends the evolution of the vaccinal pock, vaccination practised in the immediate neighborhood of a small nævus often cures that blemish, and it has been done for that purpose in many cases. It has no advantage over many other measures, however, and there is the disadvantage that the nævus may so mask the pock as to give rise to some doubt as to the satisfactory character of the latter. The practice, therefore, is not to be urged.

COMPLICATIONS.--These are local and systemic. Those of them that are at all serious are rare, and can generally be traced to fortuitous circumstances.

Inflammatory complications are usually due to undue traumatism at the time of the inoculation, to injury of the pock, or to the previous existence of a cutaneous disease or of some dyscrasia. Dermatitis is the most common. It is usually a mere erythema, but in some instances lymphangitis, lymphadenitis, phlegmonous inflammation, with diffuse suppuration, may result. From injury of the pock ulceration and gangrene may take place, and septic absorption may follow in their train. These complications are to be treated as if they had occurred from any other cause. Generally, the mere vaccination is not responsible for them, but in some instances putrescent vaccine may be adduced as their source. In such cases the complications, if they can still be called so, are apt to make their appearance long before the pock matures, even within forty-eight hours of the vaccination. Inflammatory complications supervening on the full development of the pock may invariably be set down as due to some cause not connected with the quality of the virus employed.

{469} An undue amount of dermatitis is best treated with some mildly astringent and anodyne application. The following liniment is excellent for the purpose: Rx. Unguenti Stramonii oz. j; Liquoris Plumbi Subacetatis fl. drachm ss; Olei Lini fl. oz. iv.--M. fiat linimentum. As a rule, it is best to avoid poultices applied over the pock itself, for they soften the tender structures that make up its dome and render it prone to rupture, with all the consequences that may follow its conversion into an open sore. When the latter accident has occurred, dusting powders will ordinarily suffice to absorb the discharge, and thus prevent putrefaction--either the ordinary toilet powder or salicylized or carbolized powders, the basis of which may be starch with a small proportion of the oxide of zinc. Besides the antiseptics mentioned, iodoform, boric acid, etc. may be used to advantage. Liquid applications are not usually so appropriate, but the writer has known the proprietary preparation termed Listerine to answer admirably.

Circumscribed collections of pus are to be treated as under other circumstances, and burrowing is to be guarded against. It is only in the worst cases that constitutional treatment of any sort is demanded, and in these it should be of a supporting nature.

Passing from the simple inflammatory complications to those of a specific character, we will first mention erysipelas. Genuine erysipelas following vaccination is quite rare, but when it does occur it is prone to prove serious. The writer believes that it always depends on secondary infection--i.e. that the vaccinal wound becomes the nidus of an erysipelatous contagium already existing in the patient's surroundings, just as any other traumatic surface might, and that the vaccinal virus has nothing whatever to do with it. Admitting that improper virus is apt to give rise to dangerous inflammatory complications, the latter are not really erysipelatous, whatever guise they may put on. Erysipelas following vaccination calls for no other treatment than what is proper for traumatic erysipelas under ordinary circumstances.

We now come to the subject of vaccinal syphilis. The question of the possibility of conveying constitutional taints along with vaccinia was raised long ago, but, partly relying on certain theoretical tenets, and partly because of the rarity of well-ascertained facts to shake the blind confidence felt in the utter harmlessness of vaccination, the profession fought the suggestion without properly investigating it. In regard to syphilis, the broad assertion was maintained that two infectious diseases could not affect an individual at one and the same time: either syphilis would be communicated alone or vaccinia alone; moreover, it was affirmed that the juices of a syphilitic person were not capable of giving rise to the disease by inoculation unless they happened to proceed from a syphilitic lesion. There was never sufficient basis for the former of these two doctrines, and the latter received a rude shock when it was shown by Pallizzari and the anonymous physician of the Palatinate that the blood of a syphilitic subject was capable of conveying the taint. Meantime, certain horrible outbreaks of syphilis were reported, chiefly in Italy, that could not reasonably be imputed to the ordinary occasions of syphilitic infection. Even these occurrences, however, failed to shake the general incredulity, especially in Great Britain, where until quite recently men's orthodoxy in medical matters was gauged by their obstinacy in refusing to {470} investigate, far less believe, the slightest proposition unfavorable to vaccination, and where, also, observations from beyond the limits of the empire were looked upon as in all probability fallacious.

To a Frenchman, M. Viennois, we are indebted for the first systematic and fair-minded study of the subject of vaccinal syphilis. This writer demonstrated that the Rivalta cases and those of other like outbreaks were certainly due to vaccination, but he concluded that they owed their occurrence not necessarily to the use of lymph from syphilitic subjects, but to the fact that that lymph contained blood. By this time it had come to be recognized that syphilis was inoculable by the blood. But even Viennois's masterly essay, and the facilis descensus it offered to those English authors who found themselves confronted with proof positive of their error, failed to make any noteworthy impression beyond the concession that syphilis might possibly be communicable in vaccination, but that, if it were, the catastrophe might easily be escaped by avoiding the use of lymph contaminated with blood, and that, therefore, the danger was practically no danger at all, for no one in England would think of using bloody lymph! In all this the English were slavishly followed by our own countrymen. It is proper to add, however, that Ballard of London did his best to present the matter in a proper light to the British profession, and that it is largely due to his labors and to those of Jonathan Hutchinson (the latter of whom supplemented Ricord's discovery that vaccine lymph is never free from blood with abundant clinical evidence of the existence of vaccinal syphilis unavoidable by the mere observance of Viennois's safeguard) that we are now freed from the clog of error in this matter. Nor was it the English alone that so long baffled the recognition of the truth; in the French Académie de Médicine, Jules Guérin and his adherents fought desperately against it.

At the present day we know that syphilis is liable to be communicated in vaccination, and that, too, without regard to visible blood in the lymph employed. There are two ways of avoiding it. One is, to use non-humanized lymph, since the lower animals are insusceptible to syphilis. This is simple. The other is, to select a human vaccinifer that is free from syphilis. This is difficult. Too great reliance, however, should not be placed upon the vaccinifer; it is possible to convey syphilis even in the use of bovine virus. Suppose two persons, A and B, are to be vaccinated at one sitting, A being syphilitic. If A is vaccinated first, and the same lancet, imperfectly cleansed, is used on B, it is plain that B will be inoculated not only with vaccine lymph, but also with A's blood. It is of the first importance, therefore, that this form of vaccinal inoculation of syphilis should be carefully guarded against; and that can be accomplished most certainly by using a fresh instrument for each patient.

From a medico-legal point of view it is important to note that constitutional syphilis may follow vaccination, and yet have nothing to do with it. Suppose an infant to be born syphilitic, but with no visible manifestations of the taint. Let that child be vaccinated, and let the syphilitic dyscrasia afterward break forth. The ordinary inference would be that the syphilis was due to the vaccination; and in most instances this view would certainly be urged by the syphilitic parent, since it would {471} free him from suspicion. It is always easy to disprove such an allegation, however, for syphilis communicated in vaccination always shows itself first in the form of a chancre at the site of the vaccination. Therefore in any given case, unless this mode of onset can be proved, the syphilis is manifestly not of vaccinal origin. Some observers, it is true, are of the opinion that vaccination may evoke a pre-existing syphilis, to use Lanoix's term--i.e. that it may hasten the appearance of the characteristic manifestations, and even determine their localization at the site of the vaccinal inoculation. But, even allowing the truth of that proposition, in such a case the lesion would be constitutional, not chancrous.

It is well, nevertheless, to take precautions against being placed on the defensive in this way; and it may commonly be avoided by declining to vaccinate infants under three or four months old, since inherited syphilis generally manifests itself by that time. This prudence on our own behalf should not be carried so far, however, as to lead us to deny the benefit of vaccination to very young infants whenever the prevalence of small-pox is such that they are in obvious danger of exposure.

As regards its management, vaccinal syphilis does not differ from the ordinary form of the affection, and hence demands no other treatment than what is proper for the disease contracted in the usual way. It simply originates in an extragenital chancre.

Concerning the conveyance of other constitutional taints in vaccination our knowledge is very limited. The present tendency of pathological investigation is, however, to accord inoculability to many diseases that formerly were not imagined to possess that quality, so that in regard to other affections than syphilis it is prudent to use the utmost care in the choice of lymph. There is one supposed safeguard that does not seem to have the slightest title to be so regarded--namely, the notion that a typical pock cannot be developed on a person affected with a specific cachexia. There is no truth in the doctrine. Over and over again the writer has seen perfect vaccine pocks on persons whom he knew to be syphilitic.

Cutaneous affections of a non-specific character are sometimes observed to result from vaccination; that is to say, they follow close upon its performance, without any other known exciting cause. It may fairly be supposed that in many instances they would have shown themselves even if the vaccination had not been performed, for it is often the case that we are unable to speak positively in regard to the exciting cause of an eruption. Several years ago a striking case in point was related to the writer by a well-known physician of this city, S. S. Purple, in whose practice it occurred. Purple had engaged to vaccinate a child on a certain day, but for some reason the vaccination was not done. In about a week from the appointed day, however, erysipelas made its appearance, beginning on the left arm at the usual site of vaccination, and pursued its course to a fatal termination. To be sure, we are now speaking of non-specific affections, but erysipelas illustrates the proposition perfectly, notwithstanding its specific character.

Children with a tendency to eczema are prone to suffer an outbreak of that disease as the result of vaccination. In Jenner's time, indeed, it was considered not only that there was great risk of causing an aggravation of any slight eczematous eruption by vaccination, but that the mere {472} existence of the eczema, even in the most trivial form, was likely to interfere with the success of the vaccinal inoculation. This has been the general feeling of the profession. Quite recently, however, many observations have been recorded tending to show that the old dread of vaccinating an eczematous child was not altogether warranted. The question needs further study, and, while it is probably best to postpone the operation under ordinary circumstances, nothing should induce us to withhold its protective influence where there is any manifest danger of actual exposure to small-pox.

Although eczema is the most common of the cutaneous affections called forth or aggravated by vaccination, there are various forms of skin disease, some of them difficult to classify, that occasionally result. They are usually vesicular, pustular, or furuncular--that is to say, irritative. In the majority of instances it will be found either that the pock itself has followed an irregular course, being whitish, diffuse, and ending in an exaggerated although superficial incrustation, or that it has been subjected to injury. Still, in some cases neither of these conditions is the precursor of the skin affection. In many instances the latter can only be called nondescript. There seems to be some occult connection between vaccination and the curious skin disease described by the late Tilbury Fox of London under the name of impetigo contagiosa; and, indeed, Piffard of this city has found certain microphytes to be common to the crusting period of vaccinia and that of contagious impetigo. What the relation of the two affections is to each other, however, it is difficult to say.

Apart from impetigo contagiosa, the cutaneous complications that follow in the wake of vaccination possess no distinctive features, and their management differs in no wise from that of the same manifestations due to other causes.

THE TECHNICS OF VACCINATION.--This aspect of our theme involves a number of separate considerations. It will be convenient to give our attention first to the matter of the choice of virus. The question arises at once as to the selection between animal vaccine and the humanized variety. In a broad sense the term animal vaccine includes--1. Virus derived directly from a case of so-called spontaneous cow-pox. 2. Variola vaccine--i.e. the virus of an affection of the cow resulting from variolation. 3. The virus of horse-pox (not strictly vaccinal). 4. Retro-vaccine--i.e. the virus of an affection produced in the cow by the inoculation of vaccinia from the human subject. 5. The virus of a disease (true vaccinia) propagated through a series of bovine animals from the so-called spontaneous cow-pox, being the virus now commonly understood by the term, and the variety here referred to when it is not stated to the contrary.

By humanized vaccine we understand that which is obtained from the human subject, no matter how short or how long its descent from the cow. As regards animal vaccine, we may practically exclude from consideration all but the last variety mentioned, that being the one to which, in the great majority of instances, the term is now restricted. This narrows the question down to the choice between virus that has been propagated through a number of bovine animals (practically, calves) from the spontaneous disease in the cow, and that which, whatever its original source, has already passed through the human system.

{473} The variety first mentioned, sometimes called primary vaccine, is generally spoken of by authors as not very trustworthy as regards its infective power (that is, not to be counted on to take), and as prone to give rise to undue inflammatory complications when its use does prove successful. These unpleasant qualities might be explained by the supposition that primary vaccine is not apt to be at its best when it is now and then obtained. Practically, however, it may be dismissed without further consideration, for it is seldom to be had.

The second form--variola-vaccine--is manifestly improper to be used whenever genuine vaccine is to be obtained, unless, indeed, we shut our eyes to the accumulating evidence that variola-vaccine, so called, is not vaccine at all. Furthermore, it is a question whether its use, as well as all attempts to produce it, should not be forbidden by law.

The third variety, if such it may be called, it does not seem legitimate to use in the present state of our knowledge, since it is not yet proved satisfactorily that horse-pox possesses the full protective power of cow-pox, or is free from objections that do not arise in connection with the latter.

As to retro-vaccine, while the writer is unable to see any positive reason against its use, neither can he see any reason why it should be superior to humanized vaccine, as such, save that during the period of its bovine propagation it is not liable to become contaminated with the poison of syphilis. The idea that an enfeebled stock of humanized vaccine can have new life infused into it by passing through the system of the cow is not reasonable primâ facie, and there are no particular facts to support it. By ensuring freedom from the danger of communicating syphilis retro-vaccination doubtless served a good purpose at one time, but now, since the remarkable and enduring excellence of the Beaugency stock is so well established, there seems to be no excuse for a further resort to the practice.

The last of our five forms of animal vaccine, that produced by the continued propagation of spontaneous cow-pox through calves, is what is now known as animal vaccine par excellence. Its advantages over the other forms are so obvious that it alone should figure in any comparison between animal and humanized vaccine. That being understood, what are the relative merits of animal and humanized vaccine? It should be stated, in the first place, that bovine virus should be compared with virus that has long been humanized, for lymph of but a few removes from the bovine animal does not show any noteworthy differences from animal vaccine itself.

In behalf of humanized virus it is maintained--1, that it is a more trustworthy preventive of small-pox; 2, that it is superior in its infective property, so that it is surer to take; 3, that it is more prompt in its action, thereby affording more speedy protection to persons who have actually been exposed to small-pox; 4, that its virulent property is easier of preservation, wherefore it is more to be depended on when it is necessary to keep it on hand for a long time or to transmit it to great distances; 5, that its use requires less skill, or, rather, less special knowledge of the peculiarities of the animal virus; 6, that it is less violent in its effects; 7, that it is less apt to give rise to irregular, and therefore more or less abortive and non-protective, forms of pock.

{474} The first of these propositions, which asserts that humanized vaccine confers greater protection against small-pox than the animal virus, was warmly maintained by those who opposed animal vaccination on its first introduction into this country; but now the record of the past thirteen years, during which period bovine virus has more and more borne the brunt of the fight against small-pox, has disproved it in the judgment of all competent and fair-minded observers. So far, indeed, as the facts have been analyzed, they go to show that the reverse is the case--that bovine virus confers a more complete and a more lasting protection. Direct observation on this point is strengthened by the collateral fact that revaccination became at once astonishingly successful when the use of animal vaccine first gained currency, whereas now it is again declining in success; the explanation of which latter circumstance is, that it is now found difficult to revaccinate those whose primary vaccination was done with bovine virus--a striking indication of the permanence of the protection accomplished with the latter.