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Report of the Medical Officer of Health for 1931.
26
of it is however due to the actual delay in the production of
immunity. A number of the cases shewn in this Table which have
given final negative re-tests have had one or more positive results
before the final negative one is obtained.
The 1,151 cases who have been protected gave a negative
re-Schick test within six months of having received the last dose
of immunising serum and a further 413 were negative within twelve
months. This means that 1,564 cases were known to have been
immunised within a year. There are good grounds for assuming
that a proportion of the remainder would have been found protected
if they had attended earlier to be re-tested.
In addition to the 1,751 persons who have been protected,
134 have completed the first series of injections but cannot be
recorded as protected because the last Re-schick test has given a
positive result. 68 of these have not attended since this positive
re-test. 59 of them have attended and have received a second
series of injections but have not yet been re-tested after this series.
In the other seven cases the re-Schick test after the second
series was still positive and they have received a third series of
injections.
A further 728 persons have been given immunising injections
at the Clinics but have not attended to be re-tested, so that it is
impossible to determine the value of the injections they have
received. This number includes 599 who completed the first series
of three injections and 129 who only received one or two doses.
34 susceptible persons have not yet commenced a course
of injections.
Diphtheria Following Immunising Injections:—Owing
to the fact that immunity does not develop at once it is important
to remember that a child may develop Diphtheria during the
period which elapses between the administration of the immunising
injections and the full establishment of immunity, if exposure
to infection occurs. Parents should be warned on this point.
For the same reason, if immunisation is delayed until an epidemic
of Diphtheria occurs it may easily be carried out too late to prevent
infection.