LIVE POLIO IRUS VACCINES

Poliomyelitis Vaccination in Poland with Koprowski's Live Attenuated Strains 531
The table indicates the isolation from the
samples collected before vaccination of: Type 1
virus in 11 per cent; Type 2 virus in 2.8 per
cent; and Type 3 virus in 2.2 per cent. A
cytopathogenic agent was isolated in 12.8 per
cent. Feces of 682 children vaccinated with
Type 1 virus were re-examined after an interval
of five to 14 days. In this material, poliovirus
Type 1 was isolated in 28.6 per cent of the
samples; Type 2 virus in 2.3 per cent; and Type
3 in 1.9 per cent. A cytopathogenic agent was
isolated from 23.7 per cent of the samples.
Following the administration of the Type 3
strain, samples of feces were collected from the
vaccinated children, after an interval of five
to 14 days. From the 160 samples examined,
Type 1 virus was isolated in 10 per cent; Type
2 in 0.63 per cent; and Type 3 in 43.1 per cent.
A cytopathogenic agent was isolated in 27 per
cent of the cases.
It should be noted that in the province of
Gdafisk the percentage of viruses isolated was
lower than in Warsaw. This may be due to a
relatively high percentage of persons with a
cytopathogenic agent in the feces.
Thus far, serologic investigations (the color
test) have been carried out on 254 paired sera
collected before vaccination and 30 days after
vaccination with Type 3 virus. The results obtained
are presented in Table 12. The table indicates
that among the persons examined, there
were 92 who had no antibodies against Type 1
before vaccination. After administration of the
vaccine, antibodies developed in 77 persons, i.e.,
in 78.2 per cent. So far as Type 3 was concerned,
127 persons had no antibodies before
vaccination; of these 86, or 67.7 per cent, developed
antibodies after vaccination. Of those
who had antibodies before vaccination, a fourfold
titer rise occurred in approximately 50 per
cent for both types.
The effects of the virologic and serologic
investigations, cited above, were obtained after
a mass vaccination campaign. It seems safe
to assume, therefore, that the results obtained
may serve as a proof of the immunogenic properties
of the vaccine used. Only when the
necessary epidemiologic data are collected and
the results of the virologic and serologic investigations
are in, will it be possible to evaluate
the ultimate effect of this rather large field trial.
TABLE 12.t PRELIMINARY SEROLOGICAL RESULTS IN CHILDREN FED CHAT AND Fox STRAINS
IN GDANSK*
BEFORE IMMUNIZATION
AFTER IMMUNIZATION
TYPE OF VIRUS FED
ANTIBODY
ABSENT
ANTIBODY
PRESENT
ANTIBODY
PRESENT
ANTIBODY
RISE
No. No. No. No.
1
92 - 72 (78%)
176 -· 89 (51%)
3
127 - 86 (68%)
137 -+ 76 (55%)
* Metabolic inhibition test on HeLa cells.
t Data collected by Dr. Georgiades.