LIVE POLIO IRUS VACCINES

376 Discussion
376 Discussion~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I also am well aware that much of the vaccine
that was distributed over the period from 1956 to
1958 was not as high in its potency as that which
is now being generally distributed. So, without
question, we have had a very real period of
growing pains in the development of the Salk
vaccine program in this country.
I suspect that the answer for Dr. Van Rooyen
is again the question: How-potent was the vaccine
used and what was the distribution of cases in
relationship to the vaccination in the population?
DR. ANDERSON: Dr. Langmuir made a statement
regarding the concentration of cases in
certain ethnic and various other adjectivedescribed
groups. Without questioning the fact
that a number of episodes of that kind have
occurred, I do not think we should leave the
impression that they have been confined to
that group. We had, for example, in Minnesota
last year, over 200 cases of paralytic polio (the
isolations that were made were Type 1 virus), 22
per cent of which were in persons who had had
three or four doses of Salk vaccine. There was
no concentration in ethnic or socio-economic
groups. It was a cross-section of the community.
I am certain that this holds in a great many
other places.
DR. VAN ROOYEN: I must reply to Dr. Lang.
muir's statement. Newfoundland is not a slum
area. The country tends to be underpopulated
rather than overpopulated. With regard to Dr.
Langmuir's figures regarding the efficacy of Salk
vaccine and the incidence of paralysis in those
who have received three and four shots of vac.
cine, I wonder whether this difference between
three doses and four doses of Salk vaccine is not
due to bias in the judgment of physicians who
are reluctant to make a clinical diagnosis of
poliomyelitis (without isolation of virus) in any
child who has received three or four doses of
Salk vaccine.
I would suggest that in the compilation of data
on paralytic poliomyelitis Dr. Langmuir introduce
two further data columns, one stating if
virus was isolated and the other if the clinician
was aware of the Salk vaccine status of the
patient before making a clinical diagnosis.
CHAIRMAN LÉPINE: We shall now proceed with
Dr. Sabin's paper on the "Effects of Rapid Mass
Immunization of a Population with Live, Oral
Poliovirus Vaccine under Conditions of Massive
Enteric Infection with other Viruses." This will
be followed by Dr. Ramos Alvarez's paper on the
"Use of Sabin's Live Poliovirus Vaccine in
Mexico. Results of a Large-Scale Trial."