LIVE POLIO IRUS VACCINES

DISCUSSION
CHAIRMAN VARGAS-MÉNDEZ: The meeting is
now called to order. The first part will be devoted
to reports by those who may be interested
in giving them, or to reports on programs now in
progress.
DR. SABIN: I do not know whether this is the
best time for this report; perhaps it should have
been presented at an earlier session of this Conference.
The purpose in giving it is to describe a mass
vaccination with live poliovirus vaccine, which
has been carried out in Cincinnati on 175,000
children from about three months to approximately
18 years of age, including the vast majority
of the school children.
This program was begun on 24 April, on the
initiative of the Cincinnati Board of Health. The
chief reason for this undertaking was that, as in
the rest of the country, many cases of paralytic
poliomyelitis were still occurring, particularly
in the unvaccinated preschool-age group, and in
the poorer areas of Cincinnati.
In 1959, 26 cases of poliomyelitis occurred in
Cincinnati, 13 of them preschool-age children living
in the poorer sections of the city.
At first the Board of Health decided to give
the vaccine only to the preschool-age children.
The private physicians cooperated in this program.
People could go either to their own physicians
and receive the vaccine or to clinics
established by the health department and many
hospitals. There was no charge either for the
physicians' services or for the vaccine.
The program was under the direction of the
health department and myself, and we wanted to
have all of the vaccine administered within a
period of one week. This is in line with the concept
of procedures used in eradication programs,
which I personally advocate.
Approximately 300 private physicians cooperated,
and within a period of one week they themselves
administered the vaccine to about 50,000
children, and the health department and hospital
clinics, to about 25,000 children-a total of 75,000.
591
I should tell you that Cincinnati itself has a
population of about 480,000, and together with
the surrounding county, the total is about 900,000.
The program was started only for Cincinnati
children, but very soon the county also wished to
participate. What proportion of the 75,000 children
represents the population under six I do not
know, for our census is not yet complete, but it
does represent the major proportion.
The purpose of this program was not only to
provide additional immunization, but also to
determine whether or not it might be possible by
this mass vaccination to break the chain of
transmission of polioviruses.
We also wanted to know what the immunization
effectiveness would be in a population such
as that in a city like Cincinnati, with different
socio-economic groups. Therefore, we collected
rectal swabs from over 1,000 preschool-age children
of two different socio-economic groups,
about half from those attending the clinics and
another half from those being attended by their
private physicians.
By this time, only about 600 of these 1,000
specimens have been fully tested, but I think it is
extremely interesting that even though the temperature
has already been high for 10 days in
Cincinnati-by high I mean that it reached 290
to 30 ° C.-by 24 April the incidence of enteric
viruses isolated by the same techniques we used
in Toluca was only about 4 per cent from the
children in the poor areas of the city in contradistinction
to 72 per cent that I showed you for
Toluca; and none out of 204 specimens tested
were from children attended by private
physicians.
Now, this is a very striking difference. Those
people live in crowded areas, in rather poor
houses, but have plenty of running water and
other facilities which apparently were not available
in Toluca.
We also obtained blood specimens from about
750 children, also from different socio-economie
groups, for two purposes; one, to find out what
the immune status was in the children who had