LIVE POLIO IRUS VACCINES

Immunological and Epidemiological Effectiveness of Live Polio Vaccine 487
Union Republic concerned, a system was introduced
majority of patients who had been diagnosed as
for the urgent reporting of every case having poliomyelitis. It was recommended that
diagnosed as poliomyelitis throughout the whole
Republic or Oblast.
The report, with brief information concerning
the patient, was given by telephone or telegram
a feces specimen be taken in the first few days
of illness, that a further specimen should be
taken within 10 days of the beginning of the
disease, and that the two specimens should be
to the nearest Republican Sanitational and Epidemiological
Center or Institute of Epidemiology In addition to virological examinations of
examined separately or after combination.
and Microbiology;
feces, which showed that 50 per cent of the
(2) A member of one of the groups of neuropathologists
established, was sent as quickly as of Type 1, and 15 per cent poliovirus of Types 2
patients investigated were excreting poliovirus
possible to the place where each case occurred and 3, we also carried out a serological examination
of the patients by serum titration during
to check the diagnosis and obtain basic material
for virological laboratory examination (the patient's
feces and the acute blood specimen; a In cases where the clinical diagnosis was
the period of convalescence.
second sample of blood was taken 3-4 weeks doubtful, positive laboratory findings made it
after the beginning of the illness);
possible to place the patients concerned in the
poliomyelitis group. In the case of negative
(3) Persons who contracted poliomyelitis were
laboratory data but a positive clinical diagnosis,
sent to the central Oblast and Republic's hospitals
immediately after the beginning of the
the cases to be diagnosed were considered to be
suffering from poliomyelitis.
disease. or in cases where this was impossible,
III. An important condition for carrying out
after the acute stage had passed. Experienced
neuropathologists ensured accurate diagnosis of
epidemiological analysis of the effectiveness of
vaccination was the obtaining of accurate information
concerning the numerical composition by
each case or checked the correctness of the primary
clinical diagnosis, taking into account the
age groups of the children and young people
data obtained by the laboratory examination;
vaccinated with the live vaccine or forming part
(4) For the analysis of the epidemiological
of the internal and external control groups
effectiveness of the vaccine, figures for paralytic
(Table 2).
and non-paralytic cases of poliomyelitis were
For all the groups concerned, we received
used separately. The group of patients with
from the local statistical offices information on
paralytic poliomyelitis included those with the
the composition of the population by age in
more certainly diagnosable forms of spinal and
areas covered and areas not covered by the
bulbo-spinal poliomyelitis with residual effects.
vaccination campaign.
The pontine forms, among which illnesses of a
In carrying out the vaccinations, the accurate
non-poliomyelitic nature predominated, were
registration of vaccinated children was ensured
placed in the non-paralytic group;
by means of the data from card indexes and
(5) The analysis of epidemiological effectiveness
was based on morbidity figures taken for tlie age composition of those vaccinated in the
lists and by undertaking primary analysis of
the period of the whole epidemic rise in poliomyelitis
Riayon Sanitational and Epidemiological Centers.
and covered not less than six months of Tbis information, compiled in accordance with
observation. The material on the effectiveness of a standard procedure, was summarized by the
vaccination in 1959 was processed on the basis Center or by the Epidemiology Department of
of the period June-December 1959 which began the Institute of Epidemiology and Microbiology.
three to four weeks after completion of the
Where the Republic or Oblast contained a
second immunization.
sufficiently large group of children who had been
II. A proof of the high quality of the work
done in assessing the epidemiological effectiveness
of vaccination was the completeness of the
laboratory examination of notified cases, with
full virological examination of the feces of the
given three vaccinations with the killed Salk
vaccine, we did not administer the live vaccine
to them, but kept them under observation as a
separate group, thus providing an opportunity
for settling the question of the comparative effec-