NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
96
to them more or less correctly the risks run. Vaccination has resulted in
death following either the first or the second vaccine. At other times
grave accidents, such as dangerous illness, œdemata, engorgements, etc.,
have followed it; at other times, it has not conferred immunity at all,
or only for a very short time, so that we may see sheep and cattle die
after the first and second inoculation. Animals subjected to the two
inoculations may contract fatal charbon during the first two or three
months following inoculation. We may observe very extensive œdema,
and in some cases death following the second inoculation in the horse.
Moreover, it is a generally admitted fact that vaccination for charbon is
more dangerous in the horse than in ovines or bovines; that it very
frequently gives rise to very serious œdemata and may cause severe
symptoms, even death, and that it is not advisable to have recourse to it
in these animals excepting under exceptional and urgent circumstances
such as during an epizooty. It has also been found by Biot, Lamare,
Brillant, and Duclaux, that the bad quality of food and management to
which animals are submitted exercises a great influence on the gravity of
the accidents determined by inoculation. M. Biot, after inoculating 125
cows with the premier vaccine, saw the following accidents appear: all the
beasts became ill; 25 or 30 were very ill, had much fever and consider-
able œdema; 30 to 35 were attacked by charbonous fever of a severe
character with enormous oedema, and some with secondary œdema and
colic. These accidents were explained by the bad quality of the food.
A similar observation has been made by Duclaux in Auvergne (Cantal).
Local and general accidents more or less intense according to the quality
of the food, are produced, more intense in bovines and sheep in barren
localities, where vaccination destroys ¼ or 1/6 of the sheep, whilst the same
virus only destroys 1/50 well nourished sheep.
We have also seen engorgements, with general symptoms more or
less alarming, appear in large ruminants following the inoculation with
the second vaccine. The inoculation of sheep in an advanced stage of
gestation sometimes gives rise to abortion. Young lambs may also be
rendered very ill, etc. In some cases it has happened that inoculation
has given rise to serious losses, but this is fortunately of rare occurrence.
Koch has noted the following points:—(1) that if the vaccines are too
strong, they may cause fatal charbon; (2) if they are too feeble they do
not protect; (3) that they do not confer immunity without rendering the
animal seriously ill, and that they are consequently dangerous; (4) that
vaccination may servo to disseminate charbon by rendering animals
severely ill from that disease, during which illness they are capable of
infecting others; (5) that the immunity conferred is insufficient to
preserve with certainty from natural infection; (6) that the immunity
conferred is of too short duration, etc.
97
Indications for vaccination. Duration of the immunity.
Precautions to be observed.—Despite everything, there is reason to
consider that vaccination is capable of: giving favourable results.
The accidents to which it gives rise are in reality of little importance.
Vaccinated animals ordinarily become sufficiently refractory to resist
natural infection and even experimental inoculation. It has, however,
been found that virus sent to a distance is not very easy to preserve, and
that in order to obtain the best results with the least risk, it should be
employed as soon after its preparation as possible. In order that this
may be the more easily done, laboratories have been founded in various
countries distant from France, where the attenuated virus can be pre-
pared; the efficacy of vaccination has been recgonized and attested in
all parts; it is recognized in Belgium, Spain, Italy, Switzerland, Germany,
Austria, Russia, America, Australia, etc., as in France, that it confers
immunity, and that it may be advantageously employed to preserve
animals of the ovine and bovine species from natural charbon
After
having been tested, vaccination has been practised in the above countries.
For example, in Italy, in order to render it popular, it has been decided to
deliver the vaccine free to veterinary surgeons.
Knowing the causes which may tend to aggravate the dangers of
inoculation, we should always in practice do our best to avoid or at least
to lessen them. We should not vaccinate horses, as we have already
mentioned, unless in exceptional cases. We should employ vaccines as
fresh as possible, and take care to keep them cool, sheltered from the air
and in a dark place until wanted for use; some have employed glycerine
to preserve it (Cienkowsky), but it is better to proceed as we have
already stated. We should always exercise the greatest care, and use
instruments perfectly clean, so as to avoid all mixture of impurity
or foreign germs with the virus. We should always keep in view
that the breed, age, condition of individuals, their food, etc., may
exercise a great influence on the operation; we should therefore, before
inoculating on a large scale in countries where vaccination has not
been practised, sound the ground by some preliminary trials on a small
number of subjects of various ages, breeds, etc. We should vaccinate
sheep only when not in lamb, or at an early period of gestation.
We should not vaccinate them when in an advanced stage, unless
under urgent circumstances, as when the malady is severe in the
flocks. Lambs should not be vaccinated unless there is reasonable fear of
their contracting spontaneous charbon; although it is understood that
they may receive similar doses to adults, we may content ourselves with
using smaller doses. We should choose a time to inoculate the large
ruminants when they have not to work, and for cows a time when they
are not in full milk, because vaccination causing fever, diminishes the
H
98
yield of milk, and may, if charbon should accidentally follow the opera-
tion, render the milk dangerous. Moreover, the milk of vaccinated cows
should be rejected for fifteen days after the second inoculation. It is
necessary to diminish the dose for individuals and races endowed with a
more marked susceptibility, and also for animals placed under bad
hygienic conditions, badly fed and housed, etc.
We should vaccinate for preference in the spring time, when the
disease is not so prevalent, so as to avoid the chance of increasing the
risk of vaccination being accompanied by the spontaneous disease, and
also for the reason that animals freshly vaccinated have greater resistance
to the spontaneous disease at the end of spring and during summer
when it is most generally prevalent. We should inoculate sheep at
the inside of the thigh, as has been already pointed out. With
regard to the larger ruminants, we may inoculate them behind the
shoulder, on the flank, or on the tail and ear: we should pierce the skin
with a strong needle and the injection should be made into the sub.
cutaneous tissue. The œdematous swellings which may result should be
left alone, no treatment being permitted when they are not very ex-
tensive and are unaccompanied by any alarming general disturbance.
If otherwise, we should abstain from opening them, but we may inject
into them phenicated water at 2 per cent., or iodised water. To recapitu-
late then, the evidence which is available to us has for the most part gone
to prove, despite the denial of some, that vaccination has considerably
decreased the mortality in flocks exposed to the ravages of charbon, but
it is on the other hand averred that it is not entirely free from some
dangers; there is reason then not to press its adoption, excepting in
countries where the loses from anthrax far exceed the losses consequent
on vaccination. The vaccination of bovines causing only insignificant
losses and diminishing the mortality from charbon to a considerable
extent, is indicated in all countries where the mortality from charbon
exceeds 1 or 2 per cent. The vaccination of sheep also, although it may
occasion more sensible losses, nevertheless presents notable advantages
in all countries where the mortality from charbon exceeds 3 or 4 per cent.
It should not, on the other hand, be practised imprudently; it should not
be adopted in a country where charbon does not exist, nor even in those
where it is of rare occurrence. With regard to the duration of the im-
munity conferred by Pasteur's vaccine, it has not been decided in an
absolute manner, nor has the question of the hereditary transmission of
immunity been well made out. Lambs born of Algerian mothers inocu-
lated during gestation, should be refractory to the disease according to
M. Chauveau; it cannot be the same in the case of lambs born of French
mothers during gestation (Rossignol) or even before (Toussaint). But
contradictory results have been obtained by the Commission of the
99
"Société centrale de medicine vétérinaire" on the question; the Société
d'Agriculture de Melun have noted a lamb born of a vaccinated ewe die
from inoculated charbon, and again it is generally recognized that lambs
born of vaccinated ewes do not generally enjoy immunity (Chamber-
land).
The duration of the immunity conferred by vaccination varies much
according to the strength of the virus inoculated, and according to the
degree of receptivity of the animals; it may vary from some months to
a year or more. It has been observed to last for 2, 3, 4, 5, 6, 7, 8, 9,
10 months, so it may even last 11 or 13 months, etc. Sheep may
still remain protected in a proportion of 60 per cent. after the end of a year
(Chamberland). However this may be, it may occur, as has been observed,
that immunity does not last more than 2, 3, or 4 months, etc.
The duration of the immunity seems, all other things being equal, to
be in direct proportion to the intensity of the vaccine, and of the feeble-
ness of the receptivity of the animal. To obtain lasting immunity, it is
necessary then to employ the strongest safe vaccine for animals en-
dowed with the greatest receptivity, but the dangers of vaccination are
thus increased. In all cases the degrees and the probable duration of
immunity may be gauged by the amount of re-action which follows
vaccination.
Cases have been observed of the duration of immunity for two or
three years; but it is presumed either that the immunity had been con-
ferred by the action of strong virus, or that it had been afterwards renewed
by natural infection, which, although incapable of rendering the animal
seriously ill, had contributed to perpetuate their refractory state. It has,
however, been decided that in order to perpetuate the benefits of vaccin-
ation in localities where charbon is prevalent, it is necessary to inoculate
yearly.
Chauveau's method of Vaccination.—Vaccination, with the virus
attenuated in the air, or in compressed oxygen, according to M. Chauveau's
method, has been practised with success in France, Chili and Switzerland.
It has given good results in the sheep, large ruminants and even in the
horse. The mode of operating is the same as by Pasteur's method. From
experiments made previous to and those of 1888 before the Society of
Agriculture, Melun, the following conclusions were arrived at: vaccine
prepared by the compressed oxygen method is endowed with great fixity;
it may preserve its efficiency for several months and can be transported to
great distances; it also confers complete immunity by a single inoculation;
and it does not give rise to the same amount of œdema in bovines and soli-
peds, as Pasteur's vaccine does; it enables us to confer immunity twelve or
fifteen days sooner than Pasteur's vaccine does. It may be added that
multiple and successive inoculations with the same vaccine confer a
100
more complete immunity. We may remark that immunity may be
conferred by a single inoculation with Pasteur's lymph by choosing a
strength intermediate between that of the first and second vaccines gene-
rally used. For the rest, the majority of the considerations mentioned
à propos of vaccination Pasteur apply to M. Chauveau's method; the same
rules for the mode of operating, the same precautions to be observed,
the same indications for the operation, etc., etc.
Means of conferring immunity against charbon.—The "1st
vaccine," Pasteur, produces little effect upon the rabbit; it does not injure
the adult guinea-pig, but it kills mice and very young guinea-pigs.
The "2nd vaccine," Pasteur, inoculated to the guinea-pig always
kills it and destroys also a certain percentage of rabbits. The rabbits which
resist its action may be vaccinated. When we have first inoculated the
"1st vaccine" a larger percentage of rabbits resist the second, but some
still succumb; inoculation with the 1st vaccine does not always enable
them to bear the action of the second. We are able, however, by proceeding
as M. Feltz has done at Nancy in 1882, to confer immunity on the rabbit
by subjecting it to three or four successive inoculations with virus increas-
ing virulence and intermediary between those of "1st vaccine" and that
of "the 2nd vaccine." MM. Roux and Chamberland have succeeded
in enabling the rabbit to support the "2nd vaccine" by the intravenous
injection of 4 cc of a culture of "1st vaccine," repeating it after two or
three days' interval; a week afterwards, the rabbit so treated bears the
injection of O.cc 25 of "2nd vaccine" under the skin and acquires im-
munity against charbon. The bacilli of the 1st vaccine injected in such
large numbers into the blood, disappear rapidly, accumulating in the
spleen, but do not multiply, and become rapidly destroyed, so that it is
uncertain whether the immunity from the effects of the 2nd vaccine is
due to the products of the culture or the products of the destruction of
the bacilli. According to M. G. Colin inoculations of small quantities
of charbon blood, repeated several times, may confer immunity upon the
ass, dog and horse, which may after a certain number, support the action
of an enormus injection. But all individuals do not resist these inocu-
lations with strong virus, and hence this method of proceeding does not
merit further consideration.
It appears that immunity against charbon has been produced occa-
sionally by transfusing the blood of the dog into the inoculated animals
(Rondeau) or the blood of birds; the serum contains bactericidal substan-
ces capable of preserving the organism against the invasion of the ba-
cilli; but these substances which are soluble in water, and not in alcohol,
may be destroyed by acids, by the digestive organs, and by a tempera-
ture of 45° C.
On the other hand, although certain experimentalists have main-
101
tained the contrary, it appears to have been demonstrated by others
that the serum of either dog's or frog's blood is not prophylactic. It
has, however, been found that the serum of rat's blood is endowed with
bactericidal properties "in vitro," and that if it be mixed with the bacilli
injected into the rat, it hinders or retards the development of charbon
according as the germs are in the filamentous or the spore stage. The
protection conferred by rat's serum has been made the subject of inves-
tigation by Mr. Hankin, who states that it is due to particular substances
which he has called albumoses.
It appears satisfactorily demonstrated to-day that we may create
immunity by means of chemical substances, and more especially with
the soluble products resulting from the life of the microbes. Thus,
according to Kasch, animals which have taken a sufficient quantity of
sublimate will not be susceptible to charbon: Behring says that it is
the same with those to which salts of silver have been given. According
to Woolridge we may obtain immunity for the rabbit by inoculating
him with a liquid taken from the bacilli, the liquid obtained by filtration
of a culture developed in an alkaline solution of an albuminoid substance
obtained from the thymus or the testicle.
MM. Chamberland and Roux have demonstrated, as have also Chau-
veau and Woolridge, that the bacillus secretes a material which possesses
vaccinal properties. The following is a résumé of their researches on
this subject: Toussaint had attributed the immunity to the action
of chemical substances, although in reality he was vaccinating by his
method with the attenuated microbe; MM. Chamberland and Roux have
found that it is possible to confer immunity on sheep by the sub-
cutaneous injection of charbonous blood deprived of living bacilli by
heating for 40 minutes at 55.5º C.; there exist, then, in the blood
of an animal dead of charbon, chemical substances capable of con-
ferring immunity on sheep into which a sufficient quantity is injected.
But long exposure to heat, or exposure at too elevated a degree, changes
these substances at the same time as it kills the microbes. Thus, char-
bonous blood heated for ten minutes at 100º or 115º C. loses its vaccinal
properties. It is necessary to employ a less intense heat. In reality
sheep vaccinted with decoctions of blood or of the spleen have not
resisted inoculation with the strong virus, although they have been
destroyed less quickly. One hour and a half's exposure to a temperature
of 55º C. is not sufficient to destroy all the bacilli in the blood; thus
this procedure is full of uncertainty, and it is better to have recourse
to some other to combat the microbes. M. Pasteur has adopted the
following method for the production of immunity in rabbits; he takes
blood from an animal about to die, closes it in a tube which is quite filled,
and then seals the ends; under these conditions the bacillus does not
102
multiply nor form spores, but is destroyed in 12 days at + 45º C.
whilst it lives for more than a mouth below + 17º C. MM. Cham-
berland and Roux have adopted the following method: aspirate char-
bonous blood into two tubes, fill them completely, close the ends with the
lamp, and then plunge them for an hour into a bath of water kept at
68º C.; then take them out and heat them a second time for an hour;
repeat this operation for five consecutive days; the blood so heated has
never given cultures when sown in suitable media, but its vaccinal
properties are weakened, and hence it is necessary to employ it in large
quantities. The liquid which flows from the clot from the tube
is used for inoculating sheep. Sheep which have received charbonous
blood which has been previously heated at 58º C. in sufficient quantity
inoculated into the cellular tissue, have resisted inoculation with the
strong virus; however, they have been rendered seriously ill by the
inoculation of control, which demonstrates that immunity conferred by
means of heated blood is less reliable than that brought about by the
attenuated virus. The amount of blood required to produce immunity
varies in different individuals; some have been protected by 8cc, and
others have not, even after the injection of 16cc to 32cc. Sheep
show themselves more refractory when they have received larger injec-
tions of heated blood. The immunity conferred by these methods is
not a lasting one, its duration being only for a few days; after a lapse
of 24 days it has been found that two out of every three animals have
lost the protection. Blood, prepared in the above manner and filtered,
was injected by MM. Chamberland and Roux into the vein of a sheep
in large doses. The sheep bore the injection of large quantities with-
out any sign of intoxication, but the immunity conferred was very
feeble, even less than that following subcutaneous inoculation, a fact
which might lead us to the conclusion that the vaccinal substances were
either eliminated by the kidneys or some other organ, or else partially
destroyed by oxidation. The injection of charbonous blood previously
filtered through porcelain has not succeeded in giving immunity to sheep
when inoculated into the veins. Might it not, from a consideration of
these facts, be inferred that the vaccinal material is a diastase, and
hence its alteration by heat and its not passing through a porcelain
filter.
Although charbon does not readily lend itself to a decisive demon-
stration of vaccination by chemical substances on account of the ease
with which the vaccinal material is changed by heat and re-agents, still
it remains certain that immunity can be conferred against charbon,
by means of blood deprived of bacilli, and it is the modified method
of Toussaint, by heating, which best shows it. Koch and Chamberland
consider that it is preferable to kill the microbes by the use of essences,
103
which have no action on the albuminoids nor the diastase. Essence of
mustard is recommended by Roux and Chamberland. Charbonous blood
and the fresh pulp of a charbonous spleen treated with essence of mustard
and evaporated in vacuo to eliminate the essence when its action is
completed, gives a residue which contains fixed microbian products and
which confers immunity on the rabbit with smaller doses than the same
material filtered or heated to 58º C. We may also obtain similar results
by the use of Eucalyptus (De Christmas). However, we must not lose
sight of the facts that the bacillus which produces vaccinal substances in
the organism and in the blood, produces but little in cultivations, and
that the immunity conferred by these substances is of much shorter dura-
tion than that resulting from the action of living vaccine.
G. H. Roger has performed some new experiments which have
equally demonstrated that the bacillus produces a vaccinal material.
Cultivations heated for from 5 to 10 minutes at a temperature of 110° to
115º C. were then injected into the veins of rabbits, either before or after
filtration; it appeared that it contained a vaccinal material which re-
mained in the bacilli, and which when deposited in the tissues might be
dissolved and re-absorbed in order to produce its effect. Lastly, M. Chau-
veau's experiments have demonstrated that cultures destitute of all
virulence confer immunity, which clearly proves the existence of a
vaccinal substance.
Mechanism of conferred immunity.—Conferred, like natural im-
munity, is due to the bactericidal properties of the humors and to the
phagocytic power of the cells.
Vaccination for charbon, that is to say, the production or creation of
immunity by means of attenuated virus, is an effect of the life and of the
multiplication of vaccines in the animal body by which the economy
is in some way rendered able to resist the action of bacteria and to
support their poisons (Gamaléia). If we seek to enquire more inti-
mately into the mechanism of vaccination, we find ourselves a little
embarrased, as the facts connected with the question are sometimes con-
tradictory. The following, however, is a brief résumé of the results of
various researches.
MM. Chamberland and Roux, in vaccinating the rabbit, have ob-
served that the microbes of the first vaccine inocculated subcutaneously
are rapidly destroyed at the seat of inoculation, and that those which
have been injected into the veins promptly disappear from the blood to
congregate and preserve themselves in the spleen for a longer time.
Bitter, experimenting on the sheep, has noticed that the vaccinal mi-
crobes are destroyed at the seat of inoculation, and that they do not
disseminate themselves generally. Gamaléia considers that the bacteri-
cidal state of the humors of vaccinated subjects is not due to the cells