LIVE POLIO IRUS VACCINES

Recent Experience with Lederle Trivalent Oral Poliomyelitis Vaccine 331
consideration of the various response aspects
indicated by the serologic analyses.
OBSERVATIONS
Group 1 was made up of 360 Cuban children
whose ages varied from four to 18 years, 80 per
cent of whom were between seven and 11 years
old. These children were either occupants of
welfare institutions or short-term residents in
rural recreation camps. They represent a broad
cross-section of the childhood population, and a
survey for intestinal parasites conducted in one
of the camps, revealed the fact that approximately
70 per cent were carrying two or more
species of round worm, mostly Trichuris and
Ascaris. In one camp 10 cases of varicella and
in another five cases of rubeola occurred during
the early post-feeding observation period. In a
third group an influenza-like syndrome was
prevalent, but in none of these illnesses did the
course appear unusual. I might add that Dr.
Embil saw each of these individuals personally.
Two hundred and eighty-four of these children
possessed antibody to all three types of poliovirus
at the time of oral vaccination. The remaining
76 children lacked antibody for one or more
types of virus. Incidentally, in our tests we
record only the original serum dilution. We did
not take the dilution factor into consideration.
We have stated that when they convert from negative
to 1:4, this is believed to be a significant
titer. Of course any titer greater than 1:4 is
that much better. Sixty-three were negative for
a single type, and collectively there were 91
seronegatives for one type or another among
them. The distribution of these is presented in
Table 1. You can see that we broke these down
into the monovalent, homotypic negatives, the
double negatives and the triple negatives.
Since polioimmunity occurs quite early in life
in Cuba, most of these individuals were immune;
but there were 76 persons showing the various
antibody gaps, as designated. Thus, 76 persons
showed a total of 91 antibody gaps.
Blood samples collected five to seven weeks
after administration of trivalent oral vaccine
showed that 65 of the 76 children (86 per cent),
who previously had been without antibody for
one or more types of virus, were now triple positive.
The conversion rate for the 91 pre-vaccination
negatives in terms of filled in antibody gaps
was 88 per cent, which compares favorably with
the 84 per cent conversion rate obtained previously
in comparable Cuban children when the
three virus types were fed separately. 2 Seven
of the 11 unconverted negatives were for Type 2
virus, three were for Type 1, and one was for
Type 3. You can see that after feeding the vac-
TABLE 1.
POLIOVIRUS ANTIBODY STATUS
GROUP: 76 CUBAN CHIIJBEN DATE: 1959
DOSE: 2 ML TRIVALEWT VACCINE (10'
6 1
TCD50 EACH TYPE PER DOSE)
P-VrACCINATIC ! POST-VAOCI IOB
NEGATIVE NO. OF TOTAL RV SIDAL nIGATIVgS O0. OF
TO PERSONS n0. TO TYPE COYPLETE
TYPE NGS. 1 2 3 TOTAL CONVuS lOIS
1 25 25 2 2 23
2 15 15 6 6 9
3 23 23 1 1 22
1 &2 2 4 2
1 &3 6 12 1 1 5
2&3 3 6 3
1,2 & 3 2 6 1 1 1
TOTALS 76 91 3 7 1 I 11 65 8I