LIVE POLIO IRUS VACCINES

Poliomyelitis Vaccination in Poland with Koprowski's Live Attenuated Strains 523
TABLE 1. INTRACEREBRAL INOCULATION OF MONKEYS WITH CHAT TYPE 1 POLIO VACCINE
REACTION OF MONKEYS
BATCH OF VACCINE*
CLINICAL
SIGNS
1______1________
HISTOPATHOLOGIC
LESIONS
WCH 18
WCH 18 GI
WCH 18 GI
WCH 18 GI
0/5
0/14
0/25**
0/9
0/5
2/14
0/25
0/9
Total 0/53 2/53
* Tested on 4 different days.
** Five groups of 5 monkeys each were inoculated with a dilution of 10 ° , 10-1, 10-3, 10 -3 or 10 -4.
TABLE 2. INTRASPINAL INOCULATION OF MONKEYS WITH CHAT POLIO VACCINE
Dilutions of
Vaccine - _; 10* 10 -1 10
All
Clin. Hist. Clin. Hist. Clin. Hist. Clin. Hist.
Reactions Signs Lesions Signs Lesions Signs Lesions Signs Lesions
2/9 3/9 4/10 5/10 1/5 2/5 7/24 10/2h
* Vaccine batch: WCH 18.
t Vaccine batch: WCH 18 GI.
trol test was performed 110 days after the administration
of Type 1 virus.
The results of the virologic investigation are
given in Table 5. As the table indicates,
the highest percentage of isolated strains
was obtained with a dosage of 1,000,000 TCID 50 .
The percentage isolation decreased with reduction
of the TCID,,.
In general, disregarding the dosage, Type 1
virus was isolated in 80 per cent of the cases.
It should be added that in two cases it was not
possible either to isolate the virus or to demonstrate
an increase in the antibodies. In a certain
number of cases, Type 1 virus was isolated after
30 days.
The results obtained after vaccination with
Type 3 virus are similar to those achieved when
Type 1 virus was used. The virus was isolated
in 76 per cent of the cases in all.
It should be pointed out that isolation of the
virus was attempted only on the third and
seventh days after vaccination. One cannot exclude
the possibility that more positive results
might be obtained over a prolonged observation
period.
As a result of our investigations, we were
able to establish that the strains used for vaccination
have a definite affinity for the intestinal
tract and can multiply there.
Serologic examinations performed prior to