LIVE POLIO IRUS VACCINES

Poliomyelitis Vaccination in Poland with Koprowski's Live Attenuated Strains 525
TABLE 5.
EXCRETION OF CHAT AND FOX AFTER FEEDING OF DIFFERENT DOSES
DOSE OF VACCINE
HOMOTYPIC VIRUS ISOLATIONS AFTER VACCINATION*
CHAT
Fox
(log TCID 5 o)
RATIO
PER CENT
RATIO
PER CENT
6.0
11/12
92
5.3
5.0
9/11
9/13
82
69
12/15 80
8i
8/10
80
* Stool specimens collected 3, 7, and 30 days after feeding of CHAT and 3 and 7 days after Fox.
TABLE 6.
SEROLOGIC RESPONSE TO CHAT AND Fox STRAINS
PRESENCE OF HOMOTYPIC
ANTIBODIES
STRAIN
DAYS AFTER VACCINATION
BEFORE VACCINATION >
30 60 80 110
CHAT
0/33
(0%)
26/33 17/24
(79%) (71%)
21/25
(84%)
Fox
0/25
(o%)
21/24
(88%)
25/25
(100%)
It follows from our experiments that vaccine
prepared with the Koprowski strains has definite
immunogenic properties.
In the initial stage of the oral vaccination
trial, a nurse's mistake resulted in the subcutaneous
injection of 13 children with live vaccine,
each child receiving a 1-ml. amount, containing
200,000 TCID 50 . Eight of these 13
children were seven to eight years old and had
been vaccinated twice before with Salk vaccine.
The remaining five were eight months to six
years old, and two of them had been vaccinated
once with the Salk vaccine. Three children
aged eight to 12 months had had no previous
immunization. All 13 children were given
gamma-globulin five days after the erroneous
inoculation. None of them showed any symptoms
of illness. Material from five children
(the youngest ones) was taken for viral and
serologic investigations. Of four children tested
after vaccination and gamma-globulin inoculation,
one still lacked antibody to Type 1 virus.
FIELD TRIALS
In June 1959, 642,930 children six months to
15 years of age were fed the Type 1 (CHAT)
attenuated strain. This initial trial was carried
out in two provinces only.
The campaign proper started on 20 October
1959. In March 1960, vaccinations with Type 1
were completed, and those with Type 3 ended
in April 1960. The vaccination campaign usually