xviii.
APPENDICES.
This vaccine preserves its efficacy for from six to nine months, or longer in England.
I wish during the coming year to carry out some experiments in the preparation of
vaccine glycerine of this composition to be distributed in glass capillary tubes, the inclusion
of air and the exposure of the stock of vaccine while operating on children would be thus
prevented, a fresh tube being used for each child.
For the preparation of vaccine glycerine lymph by this method, distilled water and a
grinding machine are required, and a syringe for filling into any vessels of a larger size
than capillary tubes ; these are referred to in paragraph 2 of this report under the head of
" appliances."
7. Results obtained with the vaccine paste prepared at the Government Vaccine Depôt,
Taunggyi.—As in previous years, so in the year under review, great difficulty was experi-
enced in getting Civil Surgeons to whom vaccine paste was supplied to report upon its effi-
ciency. Towards the end of the year an improvement took place in this respect, as a
result of orders issued by the Inspector-General of Jails to Civil Surgeons and Medical
officers receiving supplies of vaccine from this institution, and this difficulty is not likely
to recur in future. I ought to mention in this connection that the Civil Surgeons of a few
stations have usually reported with great regularity on the results obtained in their districts
with Taunggyi vaccine paste, notably the Civil Surgeons of Mônywa, Myaungmya, Yamè¬
thin and Lashio.
The results obtained in other districts than the Southern Shan States with Taunggyi
lymph have been confusing, in some districts very good results being obtained with vaccine
paste which in other districts proved almost a complete failure. It is notable that certain
districts obtained all through the year fairly good results, except in one or two months,
e.g., Mônywa and Yamèthin, while at other stations, e.g., Myanaung, consistently bad re-
sults were obtained with samples of the very same vaccine paste used with success in those
stations first named.
An examination of the reports received and a comparison with the results obtained at
Taunggyi and in this district with samples of the same paste as was distributed to other
stations, shows that the varying results obtained in different stations must be referred to
causes which experience has shown to lead to deterioration in the quality of vaccine lymph
paste, or to indifferent results being obtained with it.
Principal among these are—
(1) The growth of bacilli of putrefaction and other varieties in the vaccine paste.
This occurs during the rainy season more than in dry weather, and has not
been noticeable here since only glycerine has been used in preparing the
vaccine paste. Lanoline paste is more liable to deteriorate, in this way.
(2) Exposure to the air either during preparation or by the inclusion of air in the
tube in which the vaccine paste is distributed, or while in use by the vacci-
nators.
(3) Contamination of the vaccine paste with dirt during use by the vaccinator ;
this factor must be associated with the last named, namely " exposure to
air," and must produce its effect by leading to the growth of bacilli in the
vaccine paste. It can hardly come into play if the vaccine is used up
rapidly after the tube has been opened.
(4) Ignorance on the part of vaccinators of the proper method in which to use
glycerine and lanoline vaccine paste. Some vaccinators get such constant-
ly indifferent results that their want of success must be attributed to a
large extent to this factor. They fail mainly by not making the insertion
over a large-enough area and not rubbing the paste sufficiently into the
incisions.
(5) Loss of efficiency is in many cases due to staleness of the vaccine paste, i.e.,
the vaccine loses its efficacy by keeping it unused for periods of greater or
shorter lengths after preparation under certain conditions which are not yet
clearly understood, both in combination with other substances, e.g., lano-
line or glycerine, as well as when unmixed. Ordinarily, potent vaccine paste
should retain its efficacy up to at least four weeks from date of prepara-
tion. I find by experiment that Taunggyi vaccine paste made with gly-
cerine only sometimes retains its efficacy for four weeks, usually it is
efficient for three weeks, but latterly it has not retained its properties for
even four days. The feeble infective power of the vaccine-lymph used for
its preparation has been, in my opinion, certainly the cause of such rapid
deterioration of the efficiency of the paste. This cause of failure has come
into action in my own experience during two successive hot weathers,
beginning in February, extending to the beginning of April. The calves
used at the depôt at that season since no better animals could be procured,
have been in poor condition, thin and ill-nourished, and the eruption pro-
duced on them by inoculation with vaccine has always developed badly,
and the vesicles have dried up before they filled with lymph. Only a small
quantity of lymph was thus obtained from each calf, and such lymph invari-