Evening star., 1940-12-22
influenza
Continued From First Page)

A respiratory disease whose virus re-
acted with the laboratory flu virus
was influenza. Everything else was
an inf1uenZalike disease of unknown
cause. There were a great number
of minor varieties of this virus, just
sufficiently different so that an ef-
fective polyvalent vaccine could not
be produced until Rockefeller Foun-
dation workers hit upon a mixture
with the virus of dog distemper.
Again influenza B the new
vaccine would not be expected to
have any value whatever.
Nobody knows whether the great
1918 epidemic was due to A, B,
combination of both or something
which since has disappeared from
the world, There is a possibility, it
Is explained, that influenza B is a
newly evolved organism. 1t is known
that many of the plant viruses are
in an extremely active stage of evo-.
luton, throwing off new types by
the score. The same may be true
of animal disease viruses, and this
constitutes the greatest menace of
these tiniest of living organisms to
the suman race. AS soon as one is
conquered another may arise.
Found in Throat Washings.
The new virus was found by Dr.
Francis from throat washings TAX
en- from children in a mild in
f1uenza epidemic in a childrens
home at Irvington-o on-the-Hudson,
N. Y, last March. When he made
his first routine tests in the lab
oratory he realized that something
was wrong. Not only did the new
virus not react with the old but it
was extremely difficult to infect fer
rets, the experimental animals used
In most flu experiments. With great
difficulty one animal finally was
infected, and it was possible to kill
It and pass the infection along to
another animal. The only abnormal
ity noted at first was a slight blue
discoloration of the lower left lung.
At first the ferrets were only
mildly sick. BY the time large
doses had been transferred 10 times
from animal to animal, however,
the disease had become sufficiently
virulent to kill in five days. DR..
Francis now has reached the point
where ferret dies almost inva-
riably in 10 days with a solution
of about one part to a thousand
Of neutral solution.
Clears Up Some Puzzles.
The new virus clears up some puZ-
Zles. Last January and February
there was mild flu epidemic in
the South the virus of which did
not react properly, although all the
symptoms were characteristic of in
f1uenza. Some of the saved virus
from this epidemic proved identi-
cal with the new B. 1t is also
strongly suspected that it was the
cause of an epidemic in South Caro-
lima in the winter of 1887. It may
also have caused the Cuban epi-
demic this summer.
The present picture, DR.. Francis
reports, is that there are two types
of influenza in the United States
wnlcn run independent cycles OF
about two years each. Virus A must
be the most prevalent.
An attack of influenza, recent ex-
periments have shown, builds up a
degree of immunity to other attacks
within a short time. The existing
immunity, however, is probably to
Virus A. Except for the three epi-
denies cited, no known outbreak in
the United States in seven years
since A was isolated can have con-
tributed any B immunity.
I The indications are that the epi-
demic now sweeping across the
country from California is of the A
variety but this cannot be known
beyond question until tests now un-
der way in Public Health Service
laboratories are completed.