LIVE POLIO IRUS VACCINES

458
Discussion
458 Discussion~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The cases, the temporal and other relation.
ships, and other factors are being brought to
your attention. We have weeks and months of
laboratory and other work ahead of us before
we or others obtain the data necessary for making
interpretations.
Now, on the question of markers, I believe
all of us using live virus vaccines are faced with
the problem of proving or disproving paternity
of isolated polioviruses. If we go back to the
early days of blood typing, when there was only
a single set of blood types on which to depend,
one would have a very difficult time if brought
in before a group like this to prove or disprove
paternity. With the development of more and
more different sets of blood types, the solution
of paternity cases has become more certain.
Similarly, as the field of markers is widened, it
may well be possible that, by the statistical considerations
of the results of 10, 12, or maybe
more marker studies, the paternity of isolated
polioviruses may be proved.
Unfortunately, the isolation and the proof of
paternity of an agent from the feces of a patient
in a field trial area may perhaps have little relationship
to the etiology of the patient's illness.
We have saturated our community with poliovirus
and the finding of poliovirus in the stool of
patients with all types of medical and surgical
disorders is to be expected. Because of this, we
can no longer diagnose or report non-paralytic
polio. We have to report aseptic meningitis,
associated with poliovirus isolation.
We are not trying to hedge by saying that the
same should be applied to the paralytic cases,
but we, and others, are faced with a difficult
problem in diagnosis.
We have not had time to report fully on an
epidemic of infectious central nervous system
disease in St. Petersburg, Florida, another activity
of neurotropic agents in the State. The picture
is very complex and the evidence as yet
First of all, we have heard from the Minnesota
group that these strains grow well in the throat.
Secondly, we have heard that the viruses associated
with these cases, namely the Types 1 and 3,
produce viremia readily. Third, we know from
evidence which was presented last year and has
been further elaborated on, that these strains
have a greater neurovirulence than some of the
other strains we have heard about, particularly
as regards their ability to spread after gaining
a foothold in the spinal cord, after intraspinal
inoculation. Dr. Kirschstein submitted data on
this in great detail, as you remember, in earlier
meetings.
And, finally, we have to consider the possibility
that, with strains having the ability to get into
the bloodstream, which is essential for attaining
a foothold in the nervous system, and which have
the ability to spread, a small degree of reversion
here would be just enough to produce paralytic
disease.
DR. FLIPSE: Dr. Bodian, I should like to reply
first to your comment by saying that we have
revealed the complete picture as it now exists,
and that I believe this group should be very cautious
in trying to make interpretations, since we
have tried not to muddy the waters by discussing
some of the variances in opinions about these
cases.
However, I think that this assembly would
do well to realize that, in the case of patient
J. A., our group questioned the non-polio diagnosis
of the attending staff of a well-staffed military
hospital, even though their diagnosis was
based on five weeks of observation, in the absence
of laboratory and serologic evidence of polio
infection. We consider this a case that we
should investigate further.
And so we could go through each one of these
cases. I could likewise say that in four of the
cases of vaccinees serologic evidence of recent
polio infection is lacking.
To keep the record clear, I should point out
that these are complement-fixation studies, and
that our neutralization studies are not yet available.
This, 1 think, gives some indication of the lack
of evidence so necessary even for the diagnosis
of these cases, let alone the calculation of attack
or other rates.
incomplete. I think we have just presented the
problems of coincidental and temporally related
cases of illness faced by any group doing largescale
field trials. As you look into all the field
trials on Salk vaccine and all the oral vaccines,
you will find these cases. They are apparent in
all vaccine trials of any type. We present them
before this group, but more information is needed
before interpretations can be made.