Evening star., 1940-10-09

long time by veterinarians on pet
dogs. Dogs do not get flu. Men do
! not get distemper. But both are
virus diseases and there probably is
some distant relationship between
| the two families of viruses. One
theory is that human beings for
merly were as subject to distemper
as they now are TO flu, but in the
course of countless generations the
entire race has built up a complete
. immunity to it. Dogs may have
taken it over from men at a later
period and not have had time to
become immune.
In any event the virus seems to
have the power of supplementing
the stimulating effect of its probable
relative on the building up of anti
bodies in the blood. This is a
''synergistic relation" which never
could have been learned from theory,
but only from an accidental obser-
vation.
( Up to this point the Rockefeller
/ scientists had learned how to pro-
tect ferrets against flu. The next
J step was to vaccinate men, II was
not necessary then TO innoculate
i men with FLU" to test the results
After about two weeks blood speci-
mems were taken from the vacci-
mated human beings. and the serum
where the hoped-for antibodies
might be expected to appear ex-
tracted. This was then mixed with
I heavy concentrations of the flu
virus and given to ferrets-mice
may also be used to a limited
extent-by the nose route. None
of the animals developed flu This
showed that anti-bodies had been
produced in the human blood which
neutralized the organism of the
disease.
The significance hardly can be
exaggerated. But, it is stressed,
there may be unforeseen hurdles
and there is no positive proof that
any human being actually has been
| protected by the vaccine. The
Rockefeller scientists must wait for
larger epidemic than the Puerto
Rican one.
Early Efforts Thwarted.
Ever since 1918 the search for
some protection against influenza
has been thwarted. The first mis-
step was the search for bacterial
agent. Autopsies on flu victims
showed presence in the lungs of a
common micro organism which be-
came known as the influenza bac-
cilus. Most persons carry around
some in their noses and thrOats. Yet
it was found impossible to produce
the infection experimentally with
this organism.
From the first psychologists sus-
pected a viruS-invisibly minute
particle of which millions might be
contained in drop CT water.
But nothing could be gotten out
OF the blood of flu patients which
would cause the disease in animals
or other human beings. 1t was not
until 1888 that four English doc
tors-Smith, Andrews. Laidlow and
Duncan-succeeded in causing the
disease in ferrets with virus OBJ
tanned from human blood. This
triumph came at the end of a long
search financed in part by the Brit
lSh Research Council. Even the find
ing of the ferret as an experimental
animal was largely matter of luck.
The next year another virus was
isolated from some Puerto Rican
hu tho I,
worker, DR.. Thomas Francis. jr.
This strain has been carried on in
ferrets ever since and was used in
/ the present experiments. This
Puerto Rico g. promises to be-
come one of the landmarks of pro-
tective medicine.
There were two reasons for the
failure. First, it was likely that
most of the human beings to whom
attempts were made to pass the
flu already were immune to the
strains used. They had been sub
jected to the great 1918 epidemic
One may have the disease without
knowing it, but with a sufficient in
fection to cause the production Of
antibodies. Most animals are i'm
mune to it. 1t was only by luck
that the susceptibility of ferrets was
discovered.
Way Opened for Pneumonia.
Flu, per Sc, is a mild disease,
lasting about three days. While
different types cause different reac-
tions, one common to all, in both