|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.