4
REPORT OF THE KING INSTITUTE, GUINDY
PART II.—SCIENTIFIC AND G ENERAL.
(A) VACCINE LYMPH.
(1) Charge of work. —The Assistant Director Dr. C. G. Pandit was in
charge of the section throughout the year and has c ollaborated in writing this
portion of the report.
(2) Manufacture. —No changes have been introduced this year in the tech-
nique of the manufacture of lymph except as noted later on, under paragraph (5).
Nijland's method (i.e., Rabbit-Buffalo-Calf passages) continued to give satis-
factory results in maintaining the potency of Seed Lymph. The advisability of
introducing other animals in the series such as sheep, goats, donkeys, etc., either
for seed purposes or for routine lymph manufacture was investigated but satis-
factory results were not obtained.
The average yield of pulp this year was 23.7 grammes per calf as against
23.9 last year and 23.7 the year previous. Thus economy in manufacture due
to a good yield has been maintained. In all 1,195 calves were used this year as
against 1,058 last year. The small increase in the number of calves used is due
to an increase in the amount of lymph stocked to meet demands possibly larger
than usual during the off-season because, the Director of Public Health had
anticipated some increase in smallpox.
All lymph issued was repeatedly examined bacteriologically to exclude the
presence of aerobic and anaerobic pathogenic organisms.
(3) Potency of lymph. —The standard of potency has been well maintained.
As judged by the vesiculation test which is the main criterion of potency adopted
by the Institute, all the batches of lymph manufactured gave not only continuous
lines of vesiculation on calves with a 1 in 500 dilution of lymph, but "almost
continuous" lines of vesiculation with 1 in 1500 dilution.
Hitherto, lymph has been issued in a dilution of 1-5 for general use in the
Presidency. On account of the existing degree of potency, as will be noted later,
it was considered advisable to dilute the lymph further in order to lessen the
chances of post-vaccinial complications such as encephalitis. Since December
1929 it has been issued in a dilution of 1-7 for routine vaccination in the colder
months of the year. During the off-season in the hotter months when deteriora-
tion in transit is considerable and when vaccination is resorted to only for
outbreaks of smallpox, the lymph is issued in a dilution of 1-5.
The results obtained with the 1 in 7 diluted lymph issued to the local
Saidapet Range were satisfactory—giving 98.4 per cent case successes and 95.7 per
cent insertion successes as against 99.4 per cent and 95.3 per cent respectively
during the previous year. As is shown later, the general success rate in the
Presidency has been well maintained.
(4) The immunizing value of lymph. —No definite standard regarding the
immunizing value of lymph is yet available. This question was discussed in detail
in the Annual Report for 1927. It was pointed out then that on account of the
improved method of manufacture, the lymph had gained considerably in its
immunizing value against vaccinia itself. The progressive diminution in the death
- r a t e f r o m s m a l l p o x d u r i n g t h e l a s t f i v e y e a r s w a s a l s o a d d u c e d a s e v i d e n c e o f t h e
efficacy of the lymph produced. We are indebted to the Director of Public Health
and the Health Officer of the Madras Corporation for further data on this point.
In the following table, the "Vaccinial" condition of 2,522 cases of smallpox is
analysed. It is to be noted that figures obtained are from districts which are
widely separated in the Presidency. They should, therefore, serve to represent
the general "Vaccinial" condition of the Presidency.