|ASSESSMENT OF BCG VACCINATION IN INDIA; THIRD REPORT
|Kul Bhushan: Indian J Med Res 1960, 48, 406-17.
Under the auspices of the Indian Council of Medical
Research, a third assessment of the mass BCG campaign in
India was carried out from 1955-58. It is a continuation
of the work started by the WHO, of evaluating the level of allergy
among groups vaccinated in the campaign. WHO team used 5 TU RT 14,
20, 21, while the present assessment team used 5 TU RT 22.
A total of 18,367 school children distributed over 262 schools in
169 different localities were retested for post-vaccination tuberculin
sensitivity. The groups were vaccinated in mass BCG campaign
with 91 different batches of vaccine produced in Madras. The interval
between vaccination and retest varied from 1½ to 42 months.
The mean size of reactions varied from 8.3 to 16.6
with overall mean of 12.5 mm. Less than 10% of the mean values
were under 10 mm and less than 10% over 15 mm. Analysis also showed
that BCG vaccination was responsible for an increase of 6-7 mm
in the mean size of reaction over the pre-vaccination level of the
non-infected. One third of the groups had their sensitivity increased
upto 6 mm and two third by 7-11 mm. Comparing with the highest attainable
degree of tuberculin sensitivity in the infected 1/3rd of the vaccinated
group fell short of it by 5-9 mm, whereas 2/3rd were within 4 mm
of this level. There is no appreciable difference in the post-vaccination
allergy according to the state and prevalence of non- specific tuberculin
sensitivity. However, there is an increase in allergising capacity
of the BCG vaccine after introduction of modifications in the production
procedures in 1955 and again in 1956 in the BCG Laboratory at Madras.
Waning of allergy upto 20 months after vaccination and boosting
thereafter probably due to super infection was also observed. Findings
show that a large proportion of the vaccinated groups retested have
achieved attainable allergy with the vaccine used. In view of the
above, there is an urgent need to produce Freeze-Dried vaccine than
the present liquid vaccine for achieving high levels of allergy.
Freeze-Dried vaccine holds out promise for
use in the mass BCG campaign. A continued and expanded research
is needed into the protective value of BCG vaccination with the
level of allergy which the mass campaign can produce under the epidemiological
circumstances existing in India and other technically developed
|KEY WORDS: BCG VACCINATION, ASSESSMENT, TUBERCULIN
SENSITIVITY, TUBERCULIN ALLERGY, LIQUID BCG, FREEZE-DRIED BCG.
|ALLERGY AFTER BCG VACCINATION
|Kul Bhushan: Proceed 18th Natl TB & Chest Dis
Workers Conf, Bangalore, 1962, 286-89.
In view of the variable and low levels of post-vaccination
allergy elicited in the Indian Mass BCG Campaign vaccinated groups
as observed by WHO and Indian BCG Assessment Teams, some studies
were carried out to investigate some of the factors considered
having influenced the levels of post-vaccination allergy. The
reasons were potency and storage of vaccine, techniques, interval
between vaccination and retesting and tuberculins used. Potency
of the vaccine: Madras vaccine was compared with Danish vaccine.
The retest done at 3 months with 1 TU RT 23 showed 11.8 mm induration
with Danish and 11.9 mm with the Madras vaccine. Test done after
one year with 20 TU induration was 18.3 mm for both the vaccines.
It is reasonable to assume that the vaccine produced at Madras
is as potent as Danish vaccine. Storage of vaccine: A comparison
of post-vaccination allergy in respect of storage of vaccine by
the ICMR Assessment Team and by Mass Campaign Teams was carried
out in five groups of villages in the neighbourhood places where
five BCG teams were working in Tamil Nadu. The non-reactors were
vaccinated randomly by vaccines stored by either team and with the
placebo III group as control. The retest done after 3 months showed
that in all the five groups combined the mean size of indurations
vaccinated with vaccine stored by Assessment Team were more in the
vaccine stored by Mass Campaign Team. The loss of potency was 0.7
mm per week in vaccine stored by Assessment Team and 1.5 mm per
week stored by Mass Campaign Team. Techniques: The above
study was extended to five more groups vaccinated and tested by
the Mass Campaign Team. Assessment Team also vaccinated separate
groups with the same vaccine and tested on the same day. Mean size
induration for groups combined was higher for assessment team but
not significant. So, the techniques do not seem to make much difference.
Interval between vaccination & retesting: Analysis of
data collected on post-vaccination allergy in the groups vaccinated
by the Mass Campaign Teams retesting according to intervals showed
that the mean size induration decreased with the increase in interval
between vaccination and retesting from 1-20 months. Thereafter,
it rose again. These results indicate a tendency for the allergy
after vaccination to wane with passage of time. The rise is presumably
due to super infection or difference in batches of vaccine. In the
third year (not included in this paper) greater proportion of people
had bigger reactions. Besides, tuberculin used for retesting is
also found to give differences in mean size induration. Tuberculin
5 TU RT 22 gave larger reactions than 1 TU RT 23 with tween, the
differences were above 3 mm.
It can be concluded that at present Madras vaccine
is satisfactorily potent, the post-vaccination allergy is influenced
by storage of vaccine, by interval between vaccination and retesting
and type of tuberculin used for eliciting the allergy. Technique
of testing, reading and vaccination may not influence the results.
Under Indian climatic conditions the liquid vaccine should not be
used for more than 2 weeks. There is a need for Freeze-Dried vaccine.
|KEY WORDS: POST-VACCINATION ALLERGY, LIQUID
BCG, FREEZE DIRED BCG, MASS BCG CAMPAIGN.
|FREEZE-DRIED BCG VACCINE SEALED IN PRESENCE OF NITROGEN
|Kul Bhushan, GVJ Baily, SS Nair, KT Ganapathy &
Vijay Singh: Indian J Med Res 1975, 63, 1335-43.
The Freeze-Dried BCG vaccine manufactured in India
is sealed under vacuum. This though adds to its stability involves
expensive production procedures. Sealing in presence of nitrogen
is both simpler and economical. Before producing this vaccine for
use on a large scale, it was considered necessary, to study the
influence of storage at higher temperatures on the allergy inducing
capacity on the basis of the size of local lesion and viable
counts of Freeze-Dried BCG vaccine sealed either in vacuum or in
the presence of nitrogen. For this, half of the ampoules of a batch
of vaccine prepared in Madras BCG Vaccine Laboratory were sealed
in vacuum and the other in presence of nitrogen. Randomly
selected ampoules of both types of vaccine were exposed to 37o and
44o for 2, 6, and 18 weeks and another set at 4oC for 18 weeks.
Two batches of liquid BCG vaccine were made as controls: 16 types
of ampoules thus obtained were randomly repeated 5 times according
to Standard Lattice Design. About 3000 school children without BCG
scar, aged 5-14 years In Bundi and Kota districts of Rajasthan were
vaccinated as per the study design. post-vaccination allergy with
5 TU RT 22 by measuring the size of vaccination lesions was recorded
3 months later. Viable counts on samples of ampoules from Freeze-Dried
BCG vaccines exposed differently were done in the production laboratory
after 18 weeks of storage.
The vaccine in 16 types of ampoules was significantly
different. Liquid BCG vaccine resulted in higher level of allergy
and larger vaccination lesions than Freeze-Dried BCG vaccine sealed
under either method. The study has shown that Freeze-Dried BCG
vaccine sealed under either method vacuum or nitrogen, gave satisfactory
level of post-vaccination allergy and induration size of vaccination
lesions, provided the vaccine was preserved at 4oC. Storage at 37o
for more than 2 weeks and even 2 weeks storage at 44oC affected
both types of vaccine badly as shown by post-vaccination allergy
and viable counts. However, decrease in viable count with time and
temperature was more pronounced in vaccine sealed in presence of
nitrogen. Hence, there is a need to provide cold chain facility
for Freeze-Dried vaccine all throughout the period.
|KEY WORDS: LIQUID BCG, FREEZE-DRIED BCG.