35
The following table has been thus compiled, to show the occurrences, using
this "average population " as a basis :-
Daily Average Strength.
CASES.
DEATHS.
Case Mortality
percent.
Number.
Percent.
Number.
Percent.
Uninoculated
982
88
84
65
66
783
Inoculated
1,190
23
19
8
06
347
If the inoculated had suffered to the same extent as the uninoculated, they
ought to have had 100 cases with 78 deaths instead of 23 and 8; which is equal
to a reduction of 77 per cent. in attacks and 89.7 per cent. in deaths in favour of
the inoculated.
From the house-to-house investigation it was ascertained that out of 47
houses in which plague cases occurred, 31 were, at the time of the attacks,
inhabited by a mixed population of inoculated and uninoculated; while 16 contained uninoculated persons only.
The occurrences in these 31 families are as shown below.

Strength.
Cases.
Deaths.
Case mortality.
Uninoculated
179
44
29
659
Inoculated
246
19
8
312
The results shown here, when compared with those in the former table,
bring out clearly once more the danger to inoculated persons arising from the
presence of uninoculated members in their families. In spite of this however it
is found that if the inoculated had suffered to the same extent as the uninoculated
members of these houses, they should have had 60 cases and 39 deaths, instead of
19 and 8 respectively; which is equal to a reduction of 68.3 per cent. of cases
and 79.5 per cent. of deaths in favour of the inoculated.
The next table shows the distribution of the cases with reference to the
time intervening between inoculation and attack.
Cases.
Deaths.
Attacked on the day of inoculation
one day after
3
3
two days
3
2
three
3
four
five
2
Six
1
1
seven
2
eight
nine
ten
2
2
more than ten days after inoculation
7
Mr. Mehta concludes from the above table that "partial protection is
achieved after three days after inoculation, and the maximum of protection is
reached after ten days"; but it is quite admissible to argue that, as the percent-
age of case mortality is the same on the first day and the tenth after inoculation,
and shows varying results on the intermediate days, the protection really varies
very little after the first day has elapsed. It is certain however that inoculation