STATISTICS OF INOCULATIONS WITH HAFFKINE'S
ANTI-PLAGUE VACCINE.
The experience of plague and measures for its management acquired in
Bombay during the past three years has demonstrated that the ordinary means
used for "stamping out" the disease have not met with the success hoped for. It
appears to be a fact that, in a large town, once the disease has taken root, it will
re-appear year after year, and that its virulence will, for a long time, show no sign
of diminution, as is the case with some other epidemic diseases. If the disease
then cannot with certainty be " stamped out," the only other resource left is to
try to render the people of the infected town immune to plague, so that, though
living with the cause of the disease all round them, they may remain free from
attack. It is only necessary to refer to the effects of vaccination for small-pox,
to make it clear that it is not impossible to immunise a population, so that,
though the exciting cause of a disease may exist in nature all around, yet cases
of that disease are comparatively rare. It is a well-known fact that diseases,
such as small-pox, typhoid fever, cholera, &c., appear as a rule only once in the
same individual, and a person who has recovered from an attack of one of these
has the comfortable conviction that in all probability he will not suffer again.
He or she has become " immune " to that disease. The causes of immunity are
not yet properly understood, and several conflicting hypotheses have been
advanced to explain the matter; all of them extremely complicated, and none
quite satisfactory. This is not the place in which to argue for one or the other of
these, nor is it necessary to enter into a discussion of theoretical considerations.
What is attempted in the following pages, is to set forth in an unbiassed
manner the results following on a practical application of anti-plague inocula-
tion to various communities throughout India. The figures themselves are
placed before the reader, and a sufficient account of the methods used in their
collection is given to enable anyone to judge for himself of the effects actually
produced, and as to the trustworthiness or otherwise of the statistics.
As the results of three months' labour at the life-history of the plague
bacillus, Haffkine informed the Government of India, in a letter dated
16th January 1897, that he had been able to prepare an inoculation fluid, which
promised, on the analogy of the results obtained previously by Pasteur in con-
nection with anthrax and rabies, and by himself in the case of cholera, to
produce in the human organism a considerable resistance to plague. The now
well-known effect on human beings he described from its action on himself, as
he had been inoculated with a dose which turned out to be 4 times stronger
than that now fixed as the standard. Shortly afterwards, 77 leading citizens of
Bombay were inoculated to demonstrate publicly the complete harmlessness of
the operation. The preparation of the prophylactic is detailed in the British
Medical Journal for May 1897, and the Indian Medical Gazette for June 1897,
and though many improvements have since been introduced in its manufac-
ture, the principles as therein laid down, remain unaltered. The first trial of
the prophylactic on a plague-stricken community was made in the Bombay
House of Correction at Byculla. Plague broke out there on the 23rd of Janu-
ary 1897, 9 attacks with 5 deaths occurring between that date and the 29th
of the same month. On the 30th of January, 6 more cases, of which 3 proved
fatal, occurred. In the afternoon of that day inoculation was offered to the
prisoners, and about half the population of the jail volunteered. Three of the
inoculated developed plague the same evening, and all of these died. These
cases manifestly had plague in their systems already-in fact, one actually
had a visible bubo at the time of inoculation-and are therefore excluded from
the following table of results obtained in the two groups of " inoculated " and
"uninoculated ". The difference between these two groups began to be mani-
fest within 24 hours of the time of inoculation, and continued till the close of
the epidemic.
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