LIVE POLIO IRUS VACCINES

344
Efficacy-Laboratory Evidence
tion. There could therefore be no bias in the
clinical interpretation of symptoms that were
reported.
Two blood specimens drawn at about 80-day
intervals as shown in Table 2 were collected from
each participant. These were sent to the laboratory
with a label that identified their origin and
sequence by code number. The specimens in
any one pair were always tested on the same day
in the same run. But, when these pairs were
actually tested, the original identifying labels had
been replaced by a scrambled and random numbering
system that made it impossible for the
testing personnel to identify any one specimen as
to its individual origin, its set origin, or its
sequence within any one given set.
Two public health nurses were employed to
offer a generalized public health nursing service
to the participants for the duration of the
study. The public health nurses visited each participant's
home to complete the family and individual
record forms. They assisted at bleeding
TABLE 3.
OCCURRENCE OF SYMPTOMS BY CLINICAL TYPE AND BY EXPERIMENTAL GROUP DURING THE
CONTROL PERIOD
PERIOD
RESPIRATORY
VIRUS PLACEBO
GASTRO-INTESTINAL
(DIARRHEA)
VIRUS PLACEBO
FEVER ALONE
VIRUS PLACEBO
OTHER
VIRUS PLACEBO
CHILDREN()
2/22-2/28
3/ 1*-3/7
3/ 8-3/14
3/15-3/21
3/22-3/28
3/29*-4/4
4/ 5-4/11
4/12-4/18
4/19-4/22
1
2
2
2
2
2
1
2
1 1
5
1(3)
2(4)
1 (
Totals
7 5
6 3
1 0
1] 3
ADULTS(2)
2/22-2/28
3/ 1*-3/7
3/ 8-3/14
3/15-3/21
3/22-3/28
3/29*-4/4
4/ 5-4/11
4/12-4/18
4/19-4/22
1
3
1
1(6)
1(6)
Totals
1 4
1 0
0 1
2 0
* Indicates feeding dates.
(1) Total children in virus group, 60; total in placebo group, 51.
(2) Total adults in virus group, 53; total in placebo group 55.
(3) Pyelitis.
(4) One rash; one case of allergy.
(5) Rash.
(6) Abortion.