Browning chief. [volume] (Browning, Mont.) 1941-1953, 1941-07-11

to most of the Rocky mountain and
Pacific coast states. The increasing
realization of this fact and the fur
ther fact that what was then known
OF the disease was insufficient to per-
NIT intelligent attempts to control this
infection over considerable areas re-
suited in the public health service es-
tablishing the Rocky Mountain labor
atory in 1921. At that time the staff
! of the Montana state board Of en-
tomology, which had been carrying on
tick control operations, including my
self, was taken over by the public
health service and Dr. r. R. Spencer,
public health service officer, was
detailed from Washington to assume
charge Of the research work. The serv-
ice devoted its efforts entirely to re-
search, leaving the problem of tick
control work to the state. was asso-
ciated with DR.. Spencer until 1928 when
he was detailed to the National In
stitute of Health in Washington, and
the work of the laboratory has since
that time been carried on under my
direction.
Preventative Vaccine Developed
The most outstanding result of the
period during which we were associated
was the development OF a preventive
vaccine. This vaccine is prepared from
the tissues of infected ticks and is
the first vaccine of this sort to be
used for human administration. For
several years after its discovery the
cost of manufacture was very high
$50 for enough to immunlze one per-
son-and the production small-at first
enough for only a few hundred people
a year, then few thousand.
Now enough vaccine is produced an
nually for 100000 people, and the cost
of production per person vaccinated
amounts to about 81. For the manu-
facture of this vaccine millions of tick
eggs are Matched each spring and from
100000 to 100000 ticks are reared
through the larval and nymphal stages
OF the adult ticks, which are necessary
in making the vaccine.
This vaccine has been of great prac-
tical value and has removed the ex-
aggerated fear of the disease which
formerly were held and has made it
possible for the state to discontinue
tick control work. 1t is now distrib-
uted to all parts of the United States
and in Canada, and has even been
supplied for use in Brazil where it is
used for mmunization against a very
similar and possibly identical disease
The Rocky Mountain laboratory is the
only place in the world where it is
made. 1t is distributed without charge
to the physicians who administer it
New Vaccine Successful
However, the cost of this vaccine has
been high and the method of produc-
ton tedious. During recent years, there
fore, an attempt has been made tc
develop a less expensive and more
easily produced product. This work, tc
which DR.. Herald r. Cox Of the lab
oratory has devoted almost his entire
time for several years, Is apparently
about to be successful. The new vac.
cine which DR.. Cox has developed l.
prepared from the thin membrane
which surrounds the yolk sac of chick
en- eggs. For its production, spotted
fever virus Is inoculated into the yoli
Of chicken eggs which have been in.
crhated several days, and the small
bacterta-hke organism which cause.
spotted fever multiplies In great mum.
bers In the membrane Just mentioned
that is. the yoIk sac. A few days aftes
the egg y inoculated, the embryo die.
and the yolk sac u removed from tn
egg and used IN making the vaccine
Vaccine prepared IN this manner cost
only . teV oents pm pss3m and car
b manufactured n much laxuR Qnan-
Ssseed tel1 Ihszs = svEy reason h