LIVE POLIO IRUS VACCINES

vaccine combined in a mixture containing 1.0
ml. of each Type 1, 2, and 3 polioviruses with
titers of 105 ' 9, 103 ' 7 , and 10 5 .3 TCID 50 per ml., re-
198
Safety-Field Evidence of Safety
198 Safety-Field Evidence of Safety
valent vaccine seems to be safe so far as it is
concerned.
Study of the immune response and virus isolation
from stools after oral administration with spectively.
the Cox monovalent vaccine was undertaken in
eight infants aged 1 to 14 months old in Osaka
(Dr. Nishizawa) and in seven children aged six
months to four years in Fukuoka (Dr. Enjoji).
The results obtained thus far were almost the
same as those obtained in Tokyo.
Naturally infected poliovirus replaced by the
oral administered attenuated virus. Dr. Nishizawa
gave two paralytic polio patients, whose
causative agents were identified as Types 2 and
3, respectively, the different types of attenuated
poliovirus, such as Type 1 and Type 2 monovalent
vaccine. The fact that the Type 2 originally
in the patient was replaced by the Cox
Type 1 poliovirus, was proven by isolation of
virus and its identification, its pathogenicity for
mice by the IC and IS routes, and the rise of
antibodies. The same phenomenon of replacement
by the Cox attenuated polioviruses was observed
in the other patient with Type 3 poliovirus
clinical disease (Table 9).
The Sabin vaccine used as a triple vaccine.
Eight children aged from two months to 11 years
and four months were fed at once with the Sabin
The virus isolation attempts were
done from both throat swabs and stools one week
after feeding, and blood was taken for antibody
response three times monthly after feeding. As
a result, coexistence of different types of polioviruses
such as Types 1 and 2, Types 2 and 3,
and Types 1, 2, and 3, were found in both throat
swabs and stools without untoward side reaction.
All of them showed a rise in antibody titers
(Table 10).
The Cox trivalent vaccine. The Cox trivalent
vaccine was given orally at once to 15 children
and two adults. Blood was taken twice before,
and once six weeks after, administration for antibody
determination. One boy and one adult did
not give positive antibody response, but the remaining
15 showed good response.
CF antibody response after oral administration
with the Cox monovalent vaccine. Four infants,
aged from four to 14 months, were fed with eacl
type of the Cox monovalent vaccine, and blood
was taken for CF 1, 3, 8, and 12 months after
feeding. Very low titers, such as 1:4-1:16 of CF
antibody, were found temporarily in three out of
four vaccinees, one to three months after feeding.
TABLE 9.
TYPE 3 POLIOVIRUS REPLACED BY THE Cox ATTENUATED VIRUSES FED IN PARALYTIC POLIO
CASE
Name of patient
M.I.
Age
2 years old
Vaccine fed Type Type Type
2 1 3
Weeks after feeding Before 1 2 3 4 6 8
Weeks after onset of disease 1 2 '3 4 5 7 9
Type of virus.isolated from stool 2 2 1 - -
Inoculation Intracerebrally 0/5 0/5 0/5
of new
isolates into Intraspinally 0/5 5/5' 1/5 0/5
mice
Neutralizing Type 1 virus 0 ¿50x
antibody 1Type 2 virus 0 0
response
Type 3 virus 0 1l50x
"'Numerator: No. of deaths.
Denominator: No. of inoculated mice.
(Nishizawa)