Evening star., 1950-07-31
3 Types of Polio Virus
Make Control Difficult
Immunity to One Form
No Guard Against Others
By Thomus R. Henry

No Guard Against Others
By Thomas R. Henry
Three distinct types of the dreaded
polio virus now are at large in the
United States.
They vastly complicate the problems
OF explaining the spread of the disease
and the possible immunization of
threatened areas.
This has been discussed by DR.. Charles
= Armstrong, veteran research scientist Of
the National Institute of Health, who
now is trying to explain the seasonal
incidence of the disease.
In the past only one form generally
has been recognized. This is the So
called Lansing virus. It has at some
time attacked nearly 80 per cent Of the
entire middle-aged population, DR..
Armstrong says This Is shown by i'm
neurological tests of the blood serum.
In the great majority Of cases the
virus infection is relatively harmless.
A person may feel 'low" for few days,
suffer from slight headaches, or from
what seems to be a bad cold. Quite
rarely comes the nerve degeneration and
Gripping generally associated with the
disease.
Any infection of this virus, however
light, presumably gives immunity for
life.
But, Dr. Armstrong believes, infection
by one type does not confer immunity
against either Of the other known types.
There may be several not yet dis
covered.
Slow Process.
Determination of the type present/in
any given case is a SLOW laborious and
expensive process. Mice or cotton rats,
cheap experimental animals, can bs
used to test for the well-known Lansing
virus, but they seem to be completely
immune to the other two types which
attack man.
Monkeys are susceptible to all three
types. but the monkey is an expensive
animal. Some experimental progress
has been made in developing a method
of distinguishing types with blood serum
in test tubes, but nothing practical has
been achieved.
The types are indistinguishable ex-
cept for the fact that infection by one
does not confer immunity against
another. The symptoms they cause are
identical, but there is some indication
that over the past half century some
general immunity in the population as
whole has been developed against the
Lansing virus SO that its effects may not
by quite so severe as those Of the other
two. One appeared recently in Balti-
more and the other on the Pacific Coast.
The newcomers presumably are "mu-
ations" from the Lansing type, due to
cosmic rays, ultraviolet radiation, or
any other Of the causes which con-
tinually are producing new species
among the organisms.
The polio season now is well under
way throughout the East. but statistics
to date do not indicate an exceptionally
bad season.
Earthquakes come in punches They
apparently are governed by general
pattern all over the earth.
This is the conclusion Of DR.. Hugo
Benioff, earthquake specialist Of the
California Institute of Technology after
an analysis of the major spasms which
have taken place since 1904. During
this period there have been 80.
In the time covered by this study, it
is concluded, the stress or strain which
accumulates constantly in the crust Of
the earth has been released in five ac-
tive periods. Each of these has been
followed by a quiet interval, during
which the cruStal strain again accumu-
lates.
apparently" says the report, there
is some global force, like q huge key,
which alternately locks and unlocks
cracks in the earth'S crust simultane-
ously throughout the world. When the
faults are locked together, strain builds
up throughout the world: but there are
no quakes. When they are unlocked,
they move apart, rocks begin to slide
and the earth quakes.
Earth Size Varies.
Possibly the earth becomes alterna-
lively larger and smaller. When it spins
faster, due to slight changes in the tidal
forces exerted by sun and moon, it may
become larger. so that the seams may be
opened enough to unlock the stored-up
tensions"
The strain. according to DR.. Benioff,
appears to be generated in the earth's
crust at a remarkably constant rate,
but is released at an irregular rate. Ma
1or quakes used to occur at closely spaced
intervals. After period Of constant &C
tivity there would be long rest period
OF several years before activity began
again. Since 1904 these periods have
become progressively shorter.
But now, the Cal Tech report says.
we have entered a new phase where
strain is being released at the same rate
as it is generated. This means that
as long as this regularity lasts there
should be only one great quake year
somewhere on earth.
The last quake series was between 1e45
and 1948.