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.
The second assertion--that humanized virus succeeds more readily than
the bovine variety--is still maintained by many, but, it may
confidently be said, by few if any whose experience with good animal
vaccine has been large. The truth is, that every large public
vaccination service in the country is now carried on almost solely
with bovine virus, and that results are thus achieved that were not
dreamed of in former times. Individual experience cannot weigh against
this fact, but may be explained, rather, by what modicum of truth
there may be in the fifth proposition, or by the assumption (surely a
legitimate one, in view of the number of irresponsible and ignorant
purveyors of animal vaccine that have thrust themselves before the
profession since the advantages of the practice were established by
the labors of others) that those whose observation leads them to a
conclusion at variance with that reached by the great majority of
trained observers have really been unfortunate in the quality of the
virus with which they have been supplied. Whatever the explanation may
be, however, there is nothing more certain than that the use of animal
vaccine, properly carried out, is daily furnishing results that have
never been excelled, if they have been equalled, in the employment of
humanized virus on a like scale.
The third suggestion--that the humanized virus acts the more promptly
of the two, and is therefore to be preferred for immediate
protection--is plausible, since the areola (the alleged sign of
systemic infection) forms somewhat later around a pock produced by
animal virus than around one that is the result of vaccination with
the humanized variety. The difference is one of a few hours only at
the most, and it is not by any means a general occurrence; still, we
may concede that in this respect the use of humanized virus is to be
preferred under certain circumstances.
As to the fourth statement--that humanized virus is more tenacious of
its infective property--strictly speaking, there is not a particle of
truth in it. In the case of liquid lymph preserved in capillary tubes
it has the semblance of truth, but, for reasons that will be more
fully set forth hereafter, that is because it is difficult to get the
virulent portion of bovine lymph out of the tube. In the form of dried
lymph (the only form that ought to be used) animal vaccine may be sent
to all parts of the world, and may be kept any reasonable length of
time and without {475} special care, without undergoing sensible
deterioration, if tested by one who is familiar with its peculiarities
and aware of the care that should be taken in using it. Under ordinary
circumstances there is no difficulty about preserving animal vaccine
with its energy practically unimpaired.
The statement that the use of humanized virus demands less special
knowledge than that of bovine virus is conceded at once. That special
knowledge is easily mastered, however, and no man fitted to practise
medicine will look upon its acquirement as a bugbear or a hardship.
The impression, almost universal thirteen years ago, that humanized
vaccine is less severe in its local and constitutional effects than
the animal virus has been eradicated from the minds of all but those
who still follow the teachings of the older writers rather than yield
to what daily experience has been teaching during these thirteen
years, or those who reason from exceptional cases rather than from a
general drift. The truth seems to be this: with revaccinated adults
animal vaccine acts somewhat more severely than the humanized virus;
in infants, on the other hand, its action is not so violent as that of
the humanized variety.
Concerning the seventh and last claim put forward in behalf of
humanized vaccine--that it is less apt to give rise to irregular or
spurious pocks--we may say that no form of irregularity has been
observed by those who have lately used the bovine virus that was not
well known to the older writers, who founded their observations
wholly, or almost wholly, on the use of the humanized virus; nor is
there any proof that such irregularities are more common now than
formerly. The truth seems to be, that these irregular forms of pock
seem to prevail at certain times, and not at other times, regardless
of the particular stock of virus used, other things being equal. Why
this should be so we do not know, but the fact is beyond dispute.
To sum up, then, we can only say that in barely one particular--that
of promptness of action--can humanized virus justly be credited with
any superiority, while in every other essential respect it is
inferior, so far as any difference is to be observed.
What, on the other hand, are the points of superior excellence
attaching to bovine virus? Setting aside certain extravagant
assertions that have sometimes been made in its behalf, such as that
it far exceeds the humanized virus in its protective virtue (which may
be true, but is not yet proved), they may be put in general terms in
the form of a denial of all the particular claims that we have
enumerated as having been put forth for its rival. Such a denial, it
has been seen, seems to the writer to be justified, save in the one
particular that perhaps we should accord to humanized virus the merit
of speedier action, and consequently greater certainty of protection,
in cases of actual exposure to small-pox.
Besides these negative points in its favor, the foremost advantage of
animal vaccine is the guarantee it gives that, properly used, no
syphilitic contamination will result. On this point no argument is
needed, for the cow is insusceptible to syphilis.
A second consideration in its favor is, that it can always be had in
large quantities at short notice. The young practitioner of the
present day can scarcely appreciate the importance of this fact, but
whoever remembers the comparative helplessness in which, in past
years, he has found himself in the face of a sudden outbreak of
small-pox, not knowing which {476} way to turn for an adequate supply
of vaccine, will at once concede its force.
On the whole, then, it must be said that bovine virus is entitled to
the preference as a rule, but that possibly it is well to resort to
humanized lymph of early removes under the special circumstances above
referred to. On no account should long-humanized vaccine be used so
long as our present stocks of animal virus maintain the excellence
they have thus far preserved, nor should humanized virus of any sort
be preferred in the general run of cases.
Passing now to a consideration of the various forms of vaccine,
disregarding its source, there are practically these three: the crust,
liquid lymph preserved in capillary tubes, and dried lymph.
Until recently the crust, or scab, was much used in this country. Its
capability of being preserved unimpaired for a long time was a valid
excuse for this, especially in regions remote from the great channels
of communication, and it was in such districts that the use of the
crust was chiefly practised. That excuse scarcely exists now, for
there are few physicians who cannot obtain a better form of vaccine
within a very short time. The objections to the crust are two: 1. Most
crusts are inert. Especially is this true of bovine crusts, which are
wellnigh worthless. It must be confessed, however, that when once a
crust has proved itself active it may be trusted to retain its
infective property for a very long time. The writer has made
successful use of crusts seven years old that had made the voyage to
Japan and back; and they were bovine crusts too. Still, the rule is,
that crusts are untrustworthy. 2. Their use is apt to be followed by
undue inflammation, probably of septic origin, for they almost
invariably contain putrescent or readily putrescible elements. It has
even happened to the writer to cut open a crust that to all appearance
was typical and innocent, and to find in its interior a cavity
occupied by a pulpy, stinking slough. Manifestly, such material is
unfit to be introduced into the system of any human being.
In regard to liquid lymph in tubes, it is not much used in this
country, and its employment elsewhere is on the decline. At first
thought, it would seem to be the best form of all, but experience does
not bear out this view. In this form humanized lymph is vastly
superior to animal lymph, but with every possible care in charging and
sealing the tubes it is not uncommon to find their contents putrid.
There are low vegetable organisms that are supposed to prey on the
vaccinad. If there is any truth in this supposition, those organisms
are certainly favored in their destructive luxuriance by keeping the
lymph liquid, thus furnishing them with the best possible
culture-fluid. Be this as it may, the fact is well ascertained that
tube-lymph does not keep well. It has been mentioned already that
bovine lymph stored in tubes is decidedly inferior to the same form of
humanized lymph. This was long ago recognized by propagators of animal
vaccine, but the cause remained a mystery until Warlomont of Brussels
suggested that it was due to one of the physical peculiarities of
animal lymph--that, namely, as already hinted at, by virtue of which
its formed elements tend to attach themselves to any surface presented
to them, leaving the supernatant liquid a mere inert compound of
water, albumen, and salts; so that in the case of tube-lymph the
virulent elements remain attached to the glass, and only the inert
constituents {477} are really used. This theory is exceedingly
ingenious and plausible, but the writer is not aware that it has been
proved. He does know, however, that in some South American countries,
where calf lymph in tubes is used with success, the custom is to grind
the tubes to powder, and inoculate with the resulting magma, glass and
all. This practice is certainly not to be commended.
Dried lymph is the most efficient of all forms of vaccine, and, kept
as it ought to be, it retains its infective power long enough to
answer all ordinary requirements. The writer has used it three years
old with success. It may commonly be counted on for six weeks. One
fact should be borne in mind, however: the longer dried lymph has been
kept the more care is necessary in its use, for by long keeping it
becomes very hard, so that it is a work of patience to dissolve it off
from the surface on which it was deposited. Failure to accomplish its
solution is the most common cause of a lack of success in its
employment.
The various forms of stored vaccine are esteemed by the writer in the
following order: 1, dried bovine lymph; 2, dried humanized lymph; 3,
humanized tube-lymph; 4, humanized crusts; 5, bovine tube-lymph; 6,
bovine crusts.
The age and other circumstances under which it is best to vaccinate
children constitute a point for practical consideration. It may first
be mentioned that pre-natal vaccination has been advocated by some
authors; that is to say, the vaccinal infection of the foetus in utero
by vaccinating the mother during gestation. There seems to be
respectable testimony going to show that the end may thus be
accomplished, but a weighty objection arises in the fact that this
mediate vaccination of the foetus produces no physical sign of its
success, so that doubt must always be felt as to whether or not the
procedure has been efficacious. Moreover, it is seldom indeed that a
child needs protection before its birth, provided we protect the
mother, for it is well known that vaccinia will overtake and destroy
the variolous infection, even when the latter has had two or three
days' start. The practice has been chiefly urged by Bollinger. It is
not likely to come into general use.
There is no special objection to vaccinating an infant at any time
after birth, but usually it is well to defer the operation until the
child is about three months old, unless there is actual danger of
exposure to small-pox. Yet it is not well to postpone vaccination
until the period of dentition, for the combined irritation of the two
disturbing elements may prove decidedly uncomfortable if not serious.
Something is to be said as to the time of the year to be chosen. In
New York the bad custom prevails, especially among the poorer classes,
of having children vaccinated only in April, May, or June--just the
part of the year in which erysipelas is most rife. The hot months
should not generally be chosen, for any source of irritation is apt to
be felt more severely by infants during the summer heat. However, no
circumstances should be looked upon as a positive bar to vaccination
in case of actual danger of exposure to small-pox, and in large towns
children should never be taken into public conveyances or carried into
any promiscuous assemblage until they have been protected by
vaccination.
The next question is as to the part of the body that should be
selected for the inoculation. The region of the insertion of the left
deltoid muscle {478} is usually chosen--the left rather than the
right, because most nurses habitually carry an infant on their own
left arm, so that the child's left arm is uppermost, and hence less
exposed to injury. The region of the deltoid insertion is
comparatively free from the irritation of muscular contraction, and it
is easily accessible. If two insertions are made, it is well to make
one of them over the deltoid insertion and the other at a point about
an inch distant on the line of the posterior border of the same
muscle, for there the lymphatic connection with the axillary glands is
less free, so that adenitis is not so much to be feared. To avoid a
scar in a locality that may be exposed to view on certain occasions
some mothers prefer that their daughters should be vaccinated on the
lower limb. To this there is no special objection, further than that
the lower limb is rather more exposed to rough handling than the arm.
If the leg is chosen, the point of junction of the two heads of the
gastrocnemius is an eligible situation.
The actual operation is performed in various ways. The old inoculators
generally made an incision through the whole thickness of the skin, so
that a pellet of subcutaneous fat rolled up into the little wound.
This is wholly unnecessary; furthermore, it is objectionable, for it
decidedly increases the risk of inflammatory complications. Still more
to be avoided are the methods by inserting a seton imbued with the
virus and by hypodermic injection or other like procedures. The best
way is, simply to remove the horny layer of the cuticle, so as to
expose the succulent portion of the epidermis. This surface is
somewhat red, and from it a slight exudation of lymph will be
observed, but there need not be the least flow of blood. By this
procedure it is not uncommon to vaccinate a sleeping child without
waking it. It is not only admissible, but preferable, not to wound the
derma at all. Such an abrasion is easily made with an ordinary lancet,
which, contrary to the advice sometimes given, should be very sharp;
but no cutting or scratching should be done with it, only scraping
with the convex part of its edge, precisely as in using an ink-eraser.
Scratching instruments (such as the rake-like vaccinator often used or
a row of needles set in a handle) are not easy to adapt to varying
degrees of plumpness of the arm, and are apt to make too deep
scratches, one at either side, while the skin between the two is
scarcely touched. Whatever instrument is chosen, it should not be used
again until it has been thoroughly cleansed--made chemically
clean--which can be accomplished only by heating it or by wiping it
off and then dipping it into a strong disinfectant solution.
Some individuals are refractory to vaccination, but complete
insusceptibility is exceedingly rare. Various expedients have been
resorted to in rebellious cases, such as vesication with
ammonia-water, maceration of the skin for some hours with glycerine,
and the like. The writer has known these devices to succeed, but he
has not seen the slightest advantage in the plan recommended by Ceely,
that of using a wound some hours old rather than one just made,
although he has tried the experiment many times. It is not necessary
to make a large abrasion; one as large as the little finger-nail is
ample.
The next step is to apply the virus, and it should be so applied as to
bring it into contact with every part of the denuded surface. In what
is known as arm-to-arm vaccination, or its equivalent, calf-to-arm
{479} vaccination (by all means the most successful method, although
not often practicable in this country), the liquid lymph, fresh from
the vaccinifer's pock, is simply applied, when it will at once become
diffused over the abraded surface without any special pains being
taken to accomplish that end.
If dried lymph is used, particular care should be taken to see that it
is actually dissolved and transferred from the substance on which it
was dried to the abraded surface. Failure to accomplish this is the
cause of almost all the lack of success that inexperienced vaccinators
meet with. The lymph should be moistened with water, or, if it is
quite old, with glycerine, before the abrasion is made, so that it may
have time to dissolve. It should then be rubbed upon the abraded spot
vigorously, and at least for the space of a full minute.
In the use of tube-lymph no other precautions are necessary than in
arm-to-arm vaccination, but, simple as this method is, its results are
unsatisfactory.