Evening star., 1941-10-25
Of Stars, Men
And Atoms
Notebook Of Science Progress
In Laboratory. Field
And Study
By Thomas r. Henru.

/
The influenza vaccine produced last
year by Rockefeller Foundation physi-
clans is approximately so per cent effec-
tive against the most prevalent type of
the disease.
That is, when an epidemic hits pop
ulation only about halt as many of the
vaccinateS as Of the unvaccinated be-
j enrpe Il.
This X Ss1c findings from clinical ex-
perience to date just reported to the
United States Public Health Service by
the discovers Of the vaccine, Drs. F. L.
Horsfall jr, and E. H. Lennette.
The substance is produced by innocu-
lating Matching hens eggs with a mix
ture of flu virus and the virus of dog
distemper. While in Its present state it
| appears much less effective than vac
cines against such virus diseases as
smallpox it is by far the best preventive
| of influenza yet known.
The best test, the two doctors report,
was made on groups of volunteers in
| IS neutrality-suspicious.. etc.-in
| Georgia and Florida ahead OF the big
epidemic which swept across the South
| institutions was 1885. Approximately
| 1000 were vaccinated and the rest left
as controls. 1t turned out that the vac
cinations preceded the height of the
| epidemic by four months.
Says the report: "A single 'subcutane-
int of yiu
four months before the occurrence of an
epidemic of influenza significantly re-
duced the incidence of influenza A
there are two other types B and Yin
the vaccinated groups. Among volun-
teers who were given lots of vaccine
which resulted in a considerable in
crease in antibodies. the incidence of in
fluenza A was only half that among
comparable control individuals.
Protection against influenza, the re-
port points out. apparently comes from
the building up in the blood of these
so-called "antibodies." They appear
| naturally following an attack and pro-
duce immunity for short time. There
is no permanent protection against this
malady.
The vaccine. Drs Horsfall and Len
nette believe. acts in the same way as
the disease itself in stimulating the pro-
duction of antibodies by the body itself
They checked the number of antibodies
in the blood of the vaccinated individ-
uals with those in the blood of persons
| recovered for four months from an at
tack and found that the actual reduc-
ton of flu was greater than would have
been calculated.
Even large number of antibodies is
not complete protection, they point out
Some persons who seem exceptionally
we'll protected come down with the dis
ease.
Prairie chickens, common birds of
the Northwestern wheat fields, and
mosquitoes jointly are indicted as re-
sponsible for the largest epidemic of
encephalitis in history which swept
through the Northwest this summer.
The findings have just been sum-
married by DR.. James p Leake, medical
director of the United States Public
Health Service, from his own observa-
tons and the reports of field agents.
The evidence is nearly conclusive, DR..
Leake says, that the disease was essen
TALLY identical with the encephalitis. or
brain Inflammation of horses, which has
come to light in the past few years.
1t is much milder than the old type
of human encephalitis. small epidemics
of which arise every few years. This
disease often left those of its victims
who lived permanently crippled and
sometimes with distressing mental symp-
toms. There is no indication of such an
aftermath from the horse fever"
Even so, DR. Leake's statistics show,
the malady was very serious. There were
1,O80 reported cases and 96 deaths in
North Dakota. In Minnesota there were
8l5 cases with somewhat lower fatality
rate and with the heaviest incidence in
the prairie districts bordering North
Dakota. In South Dakota there were
180 cases and II deaths In Manitoba
there were 434 cases and AZ deaths,
fatality rate of 81 per cent. The part
of Saskatchewan bordering North Da-
kota had a similar heavy incidence.
Montana, Alberta and Nebraska, al
though in the same area escaped lightly.
Tests have shown, DR.. Leake says,
that the virus causing this epidemic
was identical with that recovered from
horses. 1t does not, however, appear to
be passed directly from horse to man,
although this may be possible. Few
horses suffered from the malady this
summer. There was a milder human
epidemic in the same area in 1885, but
with many more horse victims. The
biggest horse epidemic was in 1887 when
there were no human cases.
A curious feature of the epidemic this
summer was that the chief sufferers
The incidence among males between 81
and go was more thar three times that
among women. This can only be ac-
counted for, DR.. LeaKe and his col
leagues hold, by difference in exposure.
The height of the epidemic came when
the men were working in the wheat
fields. This was one of the worst
mosquito summers known in the region.
Tests have established that the disease
can be transmitted by these insects.
The best clue came, however, when a
prairie chicken shot in the center of the
North Dakota epidemic region was found
infected with the virus.