Armstrong – Table of Contents

tended to die later than the controls. These experimental results suggested a possible
protective effect of prior diphtheria toxoid immunization against the lethal action of intra-
cerebral vaccinia administration.
Despite this protection of a few mice from a cerebral virus infection by means of
a previous non-specific stimulation of the defense mechanism, Armstrong stated that the
protection did not necessarily lead to the conclusion that children could be similarly
protected from postvaccinal encephalitis. He also stated that the final test in man must, of
course (for obvious reasons), be sought in epidemiological investigation. It was in the
hope of stimulating such investigations that Armstrong reported these experimental
results. He also referred again (23) to the 1916 New York City Poliomyelitis Commission
Report which noted that among 954 poliomyelitis patients one to four years of age that
the attack rate among the Schick positive (diphtheria susceptible) was 6 to 7 times as high
as among the Schick negative (diphtheria immune) patients. He quoted the Commission’s
observation as follows: “A susceptibility to one of the less contagious diseases indicates
that the child is more apt to be susceptible to other contagious and infectious diseases”.
Armstrong, drawing on other studies from the Hygienic Laboratory, compared the
susceptibility of other groups of patients to the “highly infectious” diseases such as
measles and scarlet fever according to whether they were positive or negative by skin test
to diphtheria and scarlet fever.
In discussing the available experimental results and epidemiological studies,
Armstrong speculated that the various post infectious encephalitides, which were
apparently on the increase, might be due to a common faulty response to infections on the
part of a functionally inadequate defense mechanism. He stated that it was probable that