LIVE POLIO IRUS VACCINES

Discussion
463
The majority of children, whether of preschool
or school age, have had Salk type vaccine. 1
would estimate the number at 90 per cent. It
varies somewhat from area to area, being less in
the rural areas.
I would estimate that probably 40 per cent of
the mothers have had Salk vaccine and approximately
10 per cent of the fathers. The fathers,
for some reason, practically never get immunized.
In one area it is known that Type 1 and Type
3 were present before the vaccine was given.
DR. ERICKSON: I believe Dr. Bodian's question
went unanswered. I should like to say that when
our IBM data is tabulated, we shall have denominators
to calculate the age adjusted rates.
From these data we shall also be able to estimate
data of the population that is at risk, provided
we believe the financial expenditure to be
justified.
We have siblings in households who have been
exposed to vaccinees for several weeks, and these
data could be made into a very good retrospective
study and, if financial resources were available,
the information would be worth the cost.
My last comment is, I believe, in line with
what Dr. Flipse has mentioned. The data are
certainly too preliminary to draw any conclusions.
Consequently, we have avoided trying to
interpret our data, and we should hope that
other groups would refrain from such an interpretation
at this time.
DR. HARDY: Looking back on the planning of
this study, we are amazed at how different our
findings would have been had different decisions
been taken. Had we elected to limit vaccine
feeding to those under 20, our findings might
have been very different. Again, looking back, I
am inclined to feel that had we set this up as a
placebo-control study, our observations would
have less meaning than they do at present. We
might well have been faced with a study group
with possibly two or three cases among those fed
the vaccine. But the numbers at that level would
be so low that one really could not hope to form
any reasonable opinion from them.
Looking to the future, we are going to be faced
with precisely this difficulty. Should there be a
risk here, it is apparently in the order of one in
100,000 and in the young, of much lower order
than this. To seek to study a risk of that order
by placebo study seems to me rather impractical.
I am impressed with the need for obtaining
data in areas where the vaccine will be used. We
went into this study with full confidence that
the question of safety had been settled. We hope
that there are no serious questions there now.
However, we did feel considerable reluctance
to apply to our area, our population, with an
entirely different immunological history, the results
of findings in, for example, immunologically
so strikingly different an area as Mexico. This,
it seems to me, bespeaks the need for a continuation
of necessarily large-scale field trials in this
country.
I feel, too, that this is needed, not for one
group of strains, but probably for all, before we
can have assurance that, in the area where they
will be used, the results can be predicted reliably.
DR. ARMSTRONG: We should, I believe, commend
the workers of Dade County on their very
frank and open statements. I also believe that
the rest of us should lay aside our prejudices
and give that group not discouragement but
every encouragement. After all, there are only
seven cases, two never having been vaccinated.
To make a statistical analysis on this small number
of cases is practically impossible. We are
therefore confronted with a very difficult
problem.
I should now like to direct a few questions to
our Russian friends.
This is not said in a critical sense, because
there are different standards of surveillance and
what is proper and suitable for one country
might not be for another.
I might ask Dr. Chumakov, along with my
friend Dr. Murray from the National Institutes
of Health, if they would sanction the use of vaccine
put up in candy. One of the common fatal
poisonings in the United States is due to aspirin.
Aspirin is put up in candy capsules for children;
if they get hold of them and swallow 15, 20, 30,
or more, there is trouble.
What would happen in this country if the
product were put up in candy might be disturbing.
I do not know what would happen if children
ate two, three, four, or more times as much