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ABSTRACTS
Three brews of tissue extract vaccine were made. The first and second brews
were made from aphthous membranes of calves infected with the " Hansen-Fionie "
and the third from aphthous membranes of swine infected with " Virus 2 ". The first
vaccine in the third brew was a formalised one.
Six calves were vaccinated with the tissue extract vaccine. Two calves vacci-
nated with the second brew contracted generalised foot-and-mouth after the first vacci-
nation on account of incomplete adsorption of the virus and were of no use for purposes
of the experiment. One calf in the first brew had become solidly immune. Of three
calves in the third brew two were susceptible by contact and the third developed a sus-
picious vesicle but without pyrexia. The latter was found to be immune to the subse-
quent " tongue-test ".
(iii) Lymph vaccine.—Only one brew of lymph vaccine was made. Lymph was
collected from swine that had been inoculated into the snout, coronets and clefts of
hoofs with " Virus 2 ". The lymph was initially diluted ten times. The first vaccine
contained ten parts of 1/10 diluted lymph and ninety parts of aluminium hydroxide and
the second contained twenty parts of the diluted lymph and eighty parts of aluminium
hydroxide. Three calves were vaccinated with this vaccine. Two of them were found
to be solidly immune. The third was resistant to contact infection, but contracted
foot-and-mouth disease (without generalisation) when submitted later to the " tongue-
test ".
To sum up the results of the experiment, fourteen calves were vaccinated twice
at ten days' interval with aluminium hydroxide adsorbates of foot-and-mouth virus.
Two of these contracted foot-and-mouth following the first vaccination. This was due
to incomplete adsorption. The remaining twelve calves were exposed about three
weeks after the second vaccination, to infection by contact, which caused generalised
foot-and-mouth in six. The other six remained insusceptible to contact infection.
The latter six calves were inoculated, two to three weeks later, directly into the
mucous membrane of the tongue and jaw. While this inoculation had always induced
generalised foot-and-mouth in the control animals, only two of the six vaccinated calves
became attacked, and only one of them had shown generalisation.
[The results recorded in this article, although promising, cannot be regarded as con-
clusive on account of the small number of animals involved, and inconsistency of results
in some groups. In addition some animals were submitted to more than one immunity
test, with the result that any immunity detected at the final test could not be safely
ascribed as due solely to the vaccination.] [V. R. R.]
Inheritance of resistance of mice to enteric bacterial and neurotropic virus
infections. WEBSTER, L. T. (J. Exp. Med. 65, 2, 261-286, 1937).
PREVIOUS studies by the same author had shown that certain factors regulating the
resistance of mice to naturally induced Bacillus enteritidis infection were inborn. In
this article he has presented new data to show that, under experimental conditions resis-
tance to B. enteritidis and resistance to St. Louis encephalitis virus are inherited in a
similar and relatively definite manner but independently.