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out at 12 schools. The experience of 1935 had suggested that one
dose of A.P.T. would be sufficient to protect 92.1 per cent., but
as testing continued during 1936 it became obvious that the immunity
obtained varied widely from school to school and was, on the whole,
disappointing. The results varied from 87.2 per cent. protected
at Winn's Avenue Infants to only 60.4 per cent. at Forest Road
Infants. Of 929 completed immunisations, only 73.5 per cent.
were successful after a single dose.
The. response to artificially induced immunity will naturally
vary with the efficiency not only of the particular prophylactic used,
but also with each batch, and also with the basic natural immunity
of the sample population—in this case the particular school.
The natural immunity will again depend on several factors,
notably the percentage of diphtheria carriers at each school.
It is obvious that the protection afforded by a single dose of
A.P.T. is not satisfactory and that under no circumstances should
the subsequent Schick test be omitted.
The parents of all children found to be insufficiently protected
by one dose were invited to bring them to the Immunisation Clinic,
and all the 143 who attended were fully protected after being given
a further half-dose (i.e., 0.25 c.c.).
In the light of this experience the practice now is to give an
initial dose of 0.1 c.c. A.P.T. followed in 14 days by 0.5 c.c. By
this method 97.8 per cent. are fully protected after one month and
99.1 per cent. after two months.
Scarlet Fever Immunisation.—Dick tests for Scarlet Fever:—
Dick tests, 57; Positive, 21; Negative, 36.
Six children completed the immunising course at Brookfield
Hospital, and 15 left before completion.