LIVE POLIO IRUS VACCINES

23. VACCINATION AGAINST POLIOMYELITIS IN POLAND WITHI
KOPROWSKIPS LIVE ATTENUATED STRAINS
F. PRZESMYCKI, H. DOBROWOLSKA, B. MIRSKI,
R. STANCZYK, H. WIOR, AND A. ZALESKA
Department of Virology of the State Institute of Hygiene, Warsaw, Poland
Dr. PRZESMYCKI (presenting the paper): In
1959 trials of live attenuated vaccine, prepared
from Koprowski's Type 1 CHAT strain, were
completed. Vaccination was performed in a
small town and in three adjacent villages, with
a total population of 8,716. In all, 2,888 persons
from six months to 16 years of age were vaccinated,
or 95 per cent of the registered population
in this age group. There were no complications
among the vaccinated subjects, and an increased
antibody level was observed after vaccination.
The vaccination campaign was initiated on 20
October 1958; since then no case of poliomyelitis
has heen recorded in these localities over a period
of 18 months.
On the basis of the results of this introductory
trial, a special committee was appointed by
the Ministry of Health, which recommended the
inauguration of a mass vaccination campaign
according to the following scheme:
(1) Children from six months to seven years
of age were to he vaccinated at least twice with
Salk's inactivated vaccine before being inoculated
with the live virus.
(2) Children over seven years of age might
be vaccinated with the live vaccine, without
prior immunization with Salk vaccine.
On the basis of these recommendations, a
plan was worked out for the vaccination campaign.
The management of the campaign was
entrusted to the Provincial Public Health Laboratories.
The vaccines-Type 1 and Type 3-
were supplied by Dr. H. Koprowski and were
tested by the Department of Virology of the
State Institute of Hygiene to establish: (1) the
titer; (2) the neuropathogenic properties of the
strains for monkeys; and (3) the proper dose
of vaccine by vaccinating small groups of children.
RESULTS OF TESTS
The titer for Type 1 was 107 T 0 TCID,,; that
for Type 3 was 108 TCID,,, per ml.
522
The Type 1 vaccine (CHAT 18 GI) was inoculated
intracerebrally in 53 monkeys. No clinical
symptoms were observed. In two cases,
however, histopathologic lesions could be seen.
The same vaccine was inoculated intraspinally
in 24 monkeys. In seven cases, definite clinical
symptoms could be discerned, and in 10 monkeys,
histopathologic lesions were demonstrated
(42 per cent) (see Tables 1 and 2)..
The Type 3 vaccine (Fox) was inoculated
intracerebrally in 19 monkeys. No clinical symptoms
were observed. On the other hand, atypical
histopathologic lesions were noted in one monkey,
and typical lesions in a second animal.
Thirty monkeys received an intraspinal injection
of the same vaccine. Out of this total number,
typical clinical symptoms were observed in three
cases, doubtful symptoms in four, and histopathologic
lesions in nine (30 per cent) (see
Tables 3 and 4).
Studies were also carried out in children in
order to determine the proper dosage.
The investigation was conducted in a semiisolated
children's home, where 37 children from
six months to three years of age were observed.
Examinations of stool and blood specimens
were made before the vaccine was administered.
Koprowski's live attenuated strain, Type 1
(CHAT) was then administered orally. The
following dosages were used: 1,000,000, 200,000,
and 100,000 TCID,,. Subsequently, stool specimens
were collected from the vaccinated children
after three, seven, and 30 days. Specimens
of blood were also collected again after 30 days.
At the same time, i.e., 30 days after the first
vaccination with Type 1 CHAT and Koprowski's
Type 3, Fox strain was given to the same children.
The dosages amounted to 200,000 and
100,000 TCID,,. Stool specimens were again
collected three and seven days after the administration
of the Type 3 vaccine. Blood was also
re-examined after 30 days. The last blood con-