LIVE POLIO IRUS VACCINES

324 Discussion
INFLUENCES OF ANTIBODY LEVEL ON VIRUS EXCRETION
PREEXISTING NUMBER VIRUS EXCRETORS
TYPE I
OF
ANTIBODY TITER PERSONS NUMBER PERCENTAGE
Iz - 0 < 5 156 156 100
H l 5 < 50 24 20 86
2P Í. 50 49 31 64
kz ~~ and above
0 < 5 14 9 64
5 < 50 8 4 50
50 17 4 23
~a I and above
CHAIRMAN HILLEBOE: Thank you, Dr. Payne.
The papers you have heard are now open for
discussion.
DR. LEPINE: I should like to ask Dr. Plotkin a
question. Could he state whether the children
who have shown active resistance to vaccination
between the age of eight to 70 days were breastfed
children or bottle-fed children? In other
words, had they received human milk or artificial
milk?
The reason for my question is that a few years
ago, when we studied the establishment of carrier
state in chimpanzees after oral feeding of live
poliovirus, we found that, whereas the injection
of gamma globulin would have no effect on the
establishment of a carrier state, if gamma globulins
were simultaneously fed by mouth at the
time of infection and continued for some days, the
establishment of a carrier state could be prevented
in some cases, and thus the antibody response
resulting from infection greatly reduced.
DR. PLOTKIN: We have also been interested in
this point, Dr. Lépine.
Unfortunately, we have been unable really to
study this. In reply to your question, very few of
the infants in this study were breast-fed, owing
to the circumstances of the institution in which
the study was conducted. Of course, in those
cases where there was breast feeding, we did follow
those infants; in those few we did not
observe any effect of the breast milk on the
feeding.
We did titrate some breast milk from the
mothers; to be sure, there was polio antibody
and although I do not recall the exact figures,
they were not at a remarkably high level.
DR. Cox: I was very much interested in Dr.
Robbins' comments about feeding Dr. Sabin's
Type 1 virus to infants, in whose stools virus was
found for certain periods, followed by periods
when virus was not found, and then followed by
reappearance of virus again.
We also have been doing a study of this type.
We have fed a number of children, but have the
results on only a few at the present time.
However, one interesting observation has been
made. We fed trivalent vaccine, containing 6.1
logs per strain per dose, to a child aged five and
one half months, who happened to be the child of
the senior technician in charge of our serology
group. We found all three types to appear in the
stool for three consecutive weeks. Then Type 2
disappeared for two consecutive weeks and we
found only Types 1 and 3 to be present. Then,
much to our amazement, Type 3 disappeared, and
for two consecutive weeks we found the appear-