Table 5.
Median poliovirus neutralising antibody titres, seroprotection rates, and seroconversion rates in the per-protocol population of infants
|
Monovalent OPV2 |
Novel OPV2-c1 |
Novel OPV2-c2 |
|||
|---|---|---|---|---|---|
| Standard dose | Low dose | High dose | Low dose | High dose | |
| Median poliovirus neutralising antibody titres | |||||
| Day 0, baseline | 102, 3·83 (3·50–3·92) | 131, 3·50 (3·17–3·83) | 146, 3·17 (3·09–3·50) | 129, 3·50 (3·50–3·83) | 147, 3·50 (3·17–3·83) |
| Day 7*, after dose 1 | 56, 6·67 (5·83–7·50) | 84, 5·83 (5·00–6·50) | 97, 5·17 (4·17–6·17) | 84, 5·83 (4·83–6·50) | 97, 6·50 (5·17–6·83) |
| Day 28, after dose 1 | 97, 10·50 (10·50–10·50) | 131, 10·50 (10·50–10·50) | 143, 10·50 (10·34–10·50) | 127, 10·17 (9·83–10·50) | 146, 10·17 (10·17–10·50) |
| Day 56*, after dose 2 | 40, 10·50 (10·50–10·50) | 46, 10·50 (10·17–10·50) | 48, 10·34 (10·17–10·50) | 44, 9·83 (9·34–10·34) | 48, 10·17 (9·83–10·50) |
| Seroprotection rates | |||||
| Day 0, baseline | 77/102 (76%); 66–84 | 88/131 (67%); 58–75 | 85/146 (58%); 50–66 | 88/129 (68%); 59–76 | 103/147 (70%); 62–77 |
| Day 7*, after dose 1 | 52/56 (93%); 83–98 | 75/84 (89%); 81–95 | 85/97 (88%); 79–93 | 72/84 (86%); 76–92 | 84/97 (87%); 78–93 |
| Day 28, after dose 1 | 91/97 (94%); 87–98 | 122/131 (93%); 87–97 | 134/143 (94%); 88–97 | 115/127 (91%); 84–95 | 138/146 (95%); 90–98 |
| Non-inferiority comparison† | 1 (ref) | −0·7% [−7·4 to 6·7]‡ | −0·1% [−6·4 to 7·2]‡ | −3·3% [−10·6 to 4·5]§ | −0·7% [−5·3 to 7·9]‡ |
| Day 56*, after dose 2 | 39/40 (98%); 87–100 | 45/46 (98%); 89–100 | 48/48 (100%); 93–100 | 43/44 (98%); 88–100 | 48/48 (100%); 93–100 |
| Seroconversion rates¶ | |||||
| Day 7*, after dose 1 | 40/56 (71%); 58–83 | 45/80 (56%); 45–67 | 54/95 (57%); 46–67 | 44/83 (53%); 42–64 | 57/97 (59%); 48–69 |
| Day 28, after dose 1 | 88/96 (92%); 84–96 | 108/126 (86%); 78–91 | 121/141 (86%); 79–91 | 102/126 (81%); 73–87 | 126/146 (86%); 80–91 |
| Day 56*, after dose 2 | 38/39 (97%); 87–100 | 44/45 (98%); 88–100 | 47/48 (98%); 89–100 | 38/44 (86%); 73–95 | 48/48 (100%); 93–100 |
Data are n, median log2 (95% CI), or n/N (%); 95% CI, or difference (95% CI). Doses were as follows: monovalent OPV2 was 105·7 CCID50; low dose novel OPV2 was 105 CCID50 and high dose novel OPV2 was 106 CCID50. OPV2=type 2 oral poliovirus vaccine. CCID=cell culture infectious dose. For titres, in all cases the use of 2·50 should be interpreted as 2·50 or less and the use of 10·50 should be interpreted as 10·50 or greater.
Day 7 rates are only shown for participants who received one vaccination, day 56 rates only for those who received two vaccinations.
Difference between novel OPV2 compared with monovalent OPV2.
Non-inferiority criterion met in which the 95% CI of difference between monovalent OPV2 and novel OPV2 was within 10%.
Non-inferiority could not be seen.
Seroconversion was only measured in those participants whose initial antibody titre allowed observation of a four-fold increase.