Table 3.
Median poliovirus neutralising antibody titres and seroprotection and seroconversion rates in the per-protocol population
|
Historical control study |
Novel OPV2 study—OPV vaccinated |
Novel OPV2 study—IPV vaccinated |
|||||
|---|---|---|---|---|---|---|---|
| Monovalent OPV2, groups 1 and 2 | Novel OPV2-c1, groups 1 and 2 | Novel OPV2-c2, groups 3 and 4 | Novel OPV2-c1, group 5 | Novel OPV2-c2, group 6 | Placebo, group 7 | ||
| Poliovirus neutralising antibody titres | |||||||
| Day 0, baseline | |||||||
| N | 100 | 98 | 98 | 15 | 16 | 16 | |
| Median (95% CI), log2 | 7·83 (7·34–8·50) | 8·34 (7·83–8·83) | 8·83 (8·00–9·50) | 7·83 (6·50–9·17) | 7·17 (4·83–8·50) | 6·50 (3·83–8·00) | |
| Day 28, after dose 1 | |||||||
| N | 100 | 96 | 98 | 17 | 16 | 16 | |
| Median (95% CI), log2 | 9·67 (8·34–10·17) | 10·50 (10·50–10·50) | 10·17 (9·67–10·5) | 10·50 (10·50–10·50) | 10·50 (10·17–10·50) | 5·67 (3·50–7·83) | |
| Day 56, after dose 2* | |||||||
| N | 50 | 49 | 49 | 17 | 15 | 16 | |
| Median (95% CI), log2 | 10·17 (8·50–10·50) | 10·50 (10·50–10·50) | 10·50 (9·50–10·50) | 10·50 (10·50–10·50) | 10·50 (9·17–10·5) | 7·00 (4·50–8·50) | |
| Seroprotection rates | |||||||
| Day 0, baseline | |||||||
| N | 100 | 98 | 98 | 15 | 16 | 16 | |
| n (%; 95% CI) | 97 (97%; 92–99) | 97 (99%; 94–100) | 92 (94%; 87–98) | 14 (93%; 68–100) | 15 (94%; 70–100) | 13 (81%; 54–96) | |
| Day 28, after dose 1 | |||||||
| N | 100 | 96 | 98 | 17 | 16 | 16 | |
| n (%; 95% CI) | 97 (97%; 92–99) | 96 (100%; 96–100) | 98 (100%; 96–100) | 17 (100%; 81–100) | 16 (100%; 79–100) | 12 (75%; 48–93) | |
| Day 56, after dose 2* | |||||||
| N | 50 | 49 | 49 | 17 | 15 | 16 | |
| n (%; 95% CI) | 49 (98%; 89–100) | 49 (100%; 93–100) | 49 (100%; 93–100) | 17 (100%; 81–100) | 15 (100%; 78–100) | 13 (81%; 54–96) | |
| Seroconversion rates† | |||||||
| Day 28, after dose 1 | |||||||
| N | 62 | 55 | 47 | 10 | 12 | 12 | |
| n (%; 95% CI) | 18 (29%; 18–42) | 41 (75%; 61–83) | 24 (51%; 36–66) | 10 (100%; 69–100) | 11 (92%; 62–100) | 0 (0%; 0–26) | |
| Day 56, after dose 2* | |||||||
| N | 29 | 27 | 26 | 10 | 11 | 12 | |
| n (%; 95% CI) | 11 (38%; 21–58) | 20 (74%; 54–89) | 15 (58%; 37–77) | 10 (100%; 69–100) | 9 (82%; 48–98) | 1 (8%; 0–38) | |
Log2 titre values shown as 2·5 should be interpreted as 2·50 or less and the use of 10·50 should be interpreted as 10·50 or greater. c1=candidate 1. c2=candidate 2. IPV=inactivated poliovirus vaccine. OPV=oral poliovirus vaccine. OPV2=type 2 OPV.
*
Only includes two-dose groups.
†
Seroconversion was only measured in those whose initial antibody titre allowed observation of a four-fold increase.