LIVE POLIO IRUS VACCINES

case of poliomyelitis, if it was poliomyelitis;
again there were no residual symptoms.
Finally, poliomyelitis occurred on the sixth
day after the second inoculation with live trivalent
vaccine in the third case from whom a T-
Type 1 poliovirus strain was isolated. The child
already had a titer of 1:512 to poliovirus Type
2, and also a titer of 1:512 to a poliovirus Type 3.
As for Type 1, there were no antibodies in the
serum extracted on the third day after the onset
of illness nor on the 33rd day of the illness.
It is very difficult to interpret these results.
Is it possible to say that these cases were caused
by the vaccine virus? I think that none of us
would dare to draw such a conclusion. Taking
into account all the favorable conditions that
generally existed during such a mass immunization
campaign, it is impossible to say whether
they were usual cases of poliomyelitis or that
they were mild cases of the disease because of
the inoculation background.
Referring to the clinical picture among the
vaccinees, we had only one case with residual
symptoms among the vaccinated children. All
other patients, who had been recorded as paralytic
poliomyelitis cases, left the hospital without
any residual symptoms. I believe that if the
vaccination were to have a favorable result, all
children, even those recorded as suffering from
paralytic poliomyelitis, would leave the hospital
without residual symptoms. This would be a
great achievement.
At any rate, the statistics available at present
on paralytic poliomyelitis among the vaccinated
Discussion 465
Discuss ion 465
in 1959 include only one case with residual
symptoms.
DR. ZHDANOV: The question is whether it is
acceptable to prevent many illnesses by means of
small amount of illnesses provoked by the vaccine.
I believe such a philosophy to be a very
bad one, not acceptable in any country.
That is why we started this work on poliomyelitis,
and we carefully searched, step by step, for
all possible complications, in all experiments.
We investigated every possibility.
That is why our first field trial was undertaken
not in the summer, when it was very difficult to
understand what happens, but in the winter
season in those regions where poliomyelitis was
absent, or at least not so largely spread. Then,
only after these small experiments with a few
thousand who were vaccinated, did we go forward
to other major regions, Esthonia and so on,
where this disease was prevalent.
And do not forget, the first immunization was
carried out during the winter season in places
where all the cases could be searched and investigated.
Of course, when we started with the
last campaign, we were quite sure that complications
would be avoided in every possible way.
CHAIRMAN RHODES: The next paper to be presented
is by Dr. Plotkin on "Vaccination with
the CHAT strain of Type 1 Attenuated Poliomyelitis
Virus in Leopoldville, Belgian Congo."
Following that, we shall have Dr. Gear's presentation
on "Live Virus Vaccine Studies in
Southern Africa."