Evening star., 1940-11-16
Of Stors, Men
And Atoms :.
Notebook Of Science Progress
In Field. Laboratory
And Study

In Field. Laboratory
And Study
By Thomas r. Henry.
A high resistance against pneumonia
exists. or can be created, In . great ma
jority Of the American people.
This is the indication from expert
ments with l,o99 individuals. Just re-
| ported by DR.. Lloyd D. FELTON, of the
United States Public Health Service
After immunization with a polyvalent
pneumonia serum only SIS per cent
showed no immunity at all and many
proved resistant to doses Of pneumococci,
the bacteria responsible for the disease,
100000 times greater than that required
to kill mouse. the experimental animal
ordinarily used In pneumonia investiga-
tions.
DR.. FELTON, will carry out large-scale
experiment in Maryland this winter in
Of that State to see If the experimental
results prove valid for a general popu-
lation.
In spite Of new drugs which have re-
duced the death rate pneumonia re-
mains one of the most dreaded diseases.
Induced immunity lasts, at the best,
only a year or two and the job of i'm
dvyt y, Tyx,,k
every IL months obviously is too great
and too expensive to be considered, it is
pointed out. The probability shown by
these experiments is that relatively
small number are in real danger Of an
infection and for many of these no
amount Of immunization would do any
good. Their protection. If DR.. Felton's
theory holds good, must be built up by
other means.
The tests were made with types and
pneumococci, which are responsible
for by far the greatest number of cases.
There are indications, however, that
other factors than pneumococci anti
bodies influence resistance. For exam.
pie. DR.. FELTON, says. both alcohol and
anesthesias are known to lower 1t and
it may be possible to find other drugs
which definitely increase it, or lower the
virulence of the pneumococcus itself.
Among the facts regarding pneumonia
found by DR.. FELTON, and his co-workers:
One out Of every 500 persons in the
United States gets pneumonia each year.
Before the recent introduction Of type
serums and sulfapyradine a fourth of
these died.
Approximately third Of the popula-
ton has some degree of natural resist
ance. This number can be increased to
more than 80 per cent by incubation
with the Public Health Service serum.
found impossible to stimulate production
OF any protective substances in the blood
Nearly everybody has pneumococci in
the nose and mouth most of the time
Their virulence appears much lower in
summer than winter, but this may be
due to the fact that resistance of both
mice and men is greater during the
sunny months.
After an attack of the disease a re-
sistance is built up for from three
months to a year. The immunization
produces one which lasts from six
months to two years. After one i'm
munization, preliminary experiments
show. it is easier to give full protection
a second time
Up to 18 months no antibodes are
found in the blood and it is impossible
to stimulate any. From then on the
number who have demonstrable anti
bodies increases each year to adult life
Man harbors pneumococci with greater
frequency than any other animal and is
the only species in which there is a great
variety of types-32 in all. SAYS DR. Fell
ton: Man either furnishes the soil for
the different varieties of this bacterio-
logical seed or produces variants of a
common variety depending on biochem-
ical differences in individuals"
The possibility of contagion is still OBJ
scure. although there have been cases
where it unquestionably took place The
fact that most persons carry pneumo-
cocci around with them most of the
time. DR.. FELTON, points out, has estab-
AASAiCd WlidI 10 hIlOWu dS d CUIIlIllcIlSdl
relation between the two organisms. 1t
would be fatal for the bacteria to kill the
host. Says DR.. FELTON,:
THE greater the virulence Of the or
ganism the greater its invasiveness, but
the greater the virulence the greater the
antigenicity. In consequence, if the host
Is capable Of responding to the antigen
supplied by the pneumococcus, with the
resultant formation of antibodies the
barrier against invasion is increased and
the organism becomes virulent and
lives only on superficial tissue, or dies.
Thus the virulent organism carries
with it ability to produce disease or to
produce immunity of the host so that
the host can kill the organism. If the
purpose Of the pneumococcus is to pro-
duce disease in man or animals it Is
difficult to reconcile these two opposed
forces. Certainly the organism does its
best to keep the host alive. If the host
cannot respond to the antigenic stimu-
lus, or has natural or temporary low
resistance, whatever the cause, the re-
suit is invasion by the organism and