Table 3.
Immunogenicity results for poliovirus type 1
| 1/3 IPV-Al (n=205) | 1/5 IPV-Al (n=205) | 1/10 IPV-Al (n=204) | IPV (n=206) | Total (n=820) | |
|---|---|---|---|---|---|
| Prevaccination visit 1 | |||||
| Mean (GMT) | 13·0 (10·2–16·4) | 10·4 (8·5–12·9) | 12·7 (10·1–15·8) | 14·4 (11·5–18·1) | 12·5 (11·2–14·0) |
| Median | 11·3 | 11·3 | 11·3 | 16·0 | 11·3 |
| Seroprotection* | 125 (61·0%) | 120 (58·5%) | 125 (61·3%) | 128 (62·1%) | 498 (60·7%) |
| Post-second vaccination visit 3 (exploratory) | |||||
| Mean (GMT) | 1030·9 (778·7–1364·9) | 637·8 (476·0–854·7) | 432·0 (330·9–564·0) | 2557·3 (2091·0–3127·5) | NA |
| Median | 1448·2 | 724·1 | 512·0 | 2896·3 | NA |
| Seroprotection* | 200 (97·6%) | 196 (95·6%) | 195 (95·6%) | 206 (100·0%) | NA |
| Seroconversion (primary outcome)† | 187 (91·2%) | 188 (91·7%) | 182 (89·2%) | 197 (95·6%) | NA |
| Seroconversion‡ | 190 (92·7%) | 197 (96·1%) | 191 (93·6%) | 197 (95·6%) | NA |
| Post-third vaccination visit 4 | |||||
| Mean (GMT) | 3310·2 (2738·2–4001·5) | 2221·1 (1808·9–2727·3) | 1584·6 (1277·8–1965·1) | 3727·7 (3211·1–4327·4) | NA |
| Median | 4096·0 | 2896·3 | 1448·2 | 4096·0 | NA |
| Seroprotection* | 204 (99·5%) | 204 (99·5%) | 204 (100%) | 206 (100%) | NA |
| Seroconversion (primary outcome)† | 202 (98·5%) | 204 (99·5%) | 201 (98·5%) | 206 (100%) | NA |
| Seroconversion‡ | 203 (99·0%) | 204 (99·5%) | 201 (98·5%) | 206 (100%) | NA |
Data are for per-protocol population. IPV=inactivated polio vaccine. IPV-Al= IPV adsorbed to aluminium hydroxide. GMT=geometric mean concentration. NA=not applicable.
*
Titre ≥8.
†
Titre ≥4 × estimated maternal antibody titre and titre ≥8.
‡
Titre ≥4 × estimated maternal antibody titre.