LIVE POLIO IRUS VACCINES

DISCUSSION
CHAIRMAN BURNET: Thank you, Dr. Kirschstein.
This paper is now open for discussion.
Dr. Bodian.
DR. BODIAN: I would like to point out, first
of all, that some years ago we also attempted
to use gamma globulin to block intramuscular
inoculation. We found quite satisfactory blocking
effects, which seem to be in contradiction
to the results that Dr. Kirschstein has reported.
I wish to emphasize, however. that at the National
Institutes of Health, they were using a
minimum of 7.5 logs of virus, whereas in those
days we were lucky if we had spinal cord pools
that reached 5.5 logs. Therefore, I think one
should be careful in assessing the lack of an
inhibiting effect of the gamma globulin to realize
that the relationship of virus dose and
antibody is fundamental. This is a point we
keep coming back to year after year, irrespective
of the route of inoculation.
As far as the interpretation of the rest of
Dr. Kirschstein's story is concerned, I feel a bit
uncomfortable about assuming that the intramuscular
route is illustrating a different property
of the virus as compared with intraneural
inoculation, although the evidence certainly suggests
it. I believe that Types 2 and 3 viruses
were represented by rather fewer monkeys than
were represented with Type 1, and it is known
that infection rates by the intramuscular route
are quite variable.
It seems surprising, certainly, that the Type
1 virus of all three workers should have the
same apparent ability to do better by the intramuscular
route. I should not have expected
it, but perhaps I am wrong.
One distinctive pathogenic property which I
believe seems to be clearly established by Dr.
Kirschstein's work, and reported by others today,
is the property of spreading of virus within
the CNS.
After beginning multiplication in the central
nervous system, it appears that some of these
strains are more capable of spreading throughout
the nervous system than others., and it seems
to me that this characteristic is fairly well established.
The difference between spreading
in the nervous system and spreading from the
muscles to the spinal cord is something I am
not entirely clear about in my own mind.
DR. MOYER: 1 should like to present two tables
which, though slightly different, confirm essentially
Dr. Kirschstein's results.
Table 1 shows a number of Type 2 just mentioned
by Dr. Bodian. These were not injected
intramuscularly, but intravenously, and we attempted
to induce trauma by injecting saline
intracerebrally. All of these are Type 2 batches
and paralysis did not occur in any of them, although
in several cases lesions did appear.
98
TABLE 1.
NEUROVIRULENCE IN MONKEYS
INOCULATED INTRAVENOUSLY WITH
POLIOVIRUS VACCINE
TYPE I I
LOT
PAThOL:
1 r
NO.
T'PE
VIiS.%
LO-
SiALIE
ML ROUTE
PARAL.
RATIO
SIGNIF.
LESIONS
287 P 1 7.5 2x.5 IC 0/4 1+1?/5
296 P 10 7.5 0/5 5/5
298 P - " 0/4 0/4
," 26.8 0/5 1/5
" 10 7.5 0/4 2/5
" 26.8 0/5 1/5
*'lo base íO.
" 10 7.5 - 0/5 2/5
TABLE 2. NEUROVIRULENCE IN MONKEYS
INOCULATED INTRAVENOUSLY WITH
POLIOVIRUS VACCINE
TYPES
I AND III
LOT DOSE PATEOL:
NO VIRUS EL | ROUTE PARAL. SIGNIF.
TYPE I LOG* TRI-IEKUNOL RATIO LESIONS
166 10 8.6 1 |1 IR** 0/5 0/5
SALINE
163P 1 7.3 2x.5 IC 0/4 0/6
184P 10 7.9 " " 0/5 2/5
TYPE II:
368 10 8.3 " n 0/5 1/5
* To base 10. ** In gluteus.