LIVE POLIO IRUS VACCINES

582
Efficacy-Field Evidence
more than 2,300,000 children were inoculated
with Type 1 of the vaccine in Hungary, about
40,000 children in Bulgaria, 3,000 children in
Pekin, and about 50,000 children in Hanoi,
People's Republic of Viet Nam.
In a number of cities and oblasts live poliovirus
vaccine was successfully used in 1959 in
the period when morbidity rises (July, August
and September) with a view to possibly influencing
outbreaks and reducing the incidence of the
disease.
On 25 November 1959 the Presidium of the
USSR Academy of Medical Sciences again discussed
the results of study and use of the live
anti-poliomyelitis vaccine made from the Sabin
strains and approved the large-scale utilization
of the vaccine for specific prophylaxis in the
USSR. The USSR Ministry of Health issued a
decree concerning the oral immunization with
live vaccine of the whole population of the
Soviet Union between two months and 20 years
of age in 1960. The vaccination program envisages
the immunization of 75,000,000 persons
during 1960, 52,000,000 of them before July.
The Poliomyelitis Institute of the USSR Academy
of Medical Sciences (Director M. P. Chumakov)
was entrusted the task of supplying
the whole country with live vaccine and giving
guidance on methods of use. In fulfillment of
this task, the Institute drew up instructions on
methods of organizing vaccination with the five
vaccine; these instructions were approved by
the Ministry.
Preliminary results of the implementation in
1960 of the mass immunization program in the
Soviet Union, covering persons up to 20 years
of age, showed the following features.
In the first three months of 1960, 104,283,000
vaccinal doses of live vaccine prepared in Moscow
from the A. B. Sabin strains were distributed
throughout the country. They included
64,791,000 doses of monovaccine of Type 1,
19,558,000 doses of monovaccine of Type 3,
5,297,000 doses of monovaccine of Type 2, and
14.637,000 doses of a trivalent mixture of Types
1, 2, and 3 used in the re-vaccination of persons
to whom single types of the live vaccine had
been administered earlier (2,704,000 doses of
the trivalent vaccine were used for primary
vaccination) (see Table 2).
In the RSFSR, the Ukrainian SSR, Latvia.
and Armenia, three-stage vaccination with monovaccines
will be carried out. In some oblasts of
the Ukraine a trivalent mixture has been administered
twice, while in the remaining oblasts
monovaccines have been administered separately.
Taking into account the usual wastage which
occurs (15-20 per cent) in the distribution of
vaccine during a campaign, it can be estimated
that in the first quarter of 1960 Type 1 of the
live poliovirus vaccine was administered to about
55 million persons in the Soviet Union (roughly
70 per cent of the population under 20 years of
age). Of these, about 15 million have also been
given in 1960 a monovaccine of Type 3 and
about 4 million persons have been given all
three doses. Over 14 million persons to whom
a live vaccine was administered in 1959 have
been revaccinated under the 1960 program.
Vaccinations continued successfully in the second
quarter of 1960. The results of this work
are set out in Tables 1 and 2.
In addition to ensuring the implementation of
the internal program of large-scale vaccination
against poliomyelitis with the live vaccine
made from the Sabin strains, the Soviet Union,
as part of its friendly assistance to those countries,
has sent vaccines of Type 1 and 3 separately
for 2,500,000 children in Hungary, of
Type 3 and Type 2 for between 2,500,000 and
2,000,000 persons in Czechoslovakia, for 1,500,-
000 persons in Viet Nam, and 2,200,000 in Bulgaria.
In addition, small quantities have been
sent to Albania and China.
We do not doubt but what the extensive program
of live vaccine administration we have
outlined will be fulfilled. Of course, such a
scale and rate of anti-poliomyelitis vaccination
would be quite impossible with the killed-virus
Salk vaccine. Only oral immunization with live
poliovirus vaccine makes it possible to carry out
mass vaccination of the susceptible population
within a short period. This is a guarantee of
radical prophylaxis against poliomyelitis epidemics.
The organization of the campaign and observation
of those vaccinated have been carried out
under the direct guidance, so far as method is
concerned, of members of the staff of the Poliomyelitis
Institute and the Virology Department
of the Leningrad Institute of Experimental Medicine
of the USSR Academy of Medical Sciences.
The vaccines were administered by district