Table 4.
Immunogenicity results for poliovirus type 2
| 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) | 47·4 (38·3–58·7) | 46·4 (38·4–56·1) | 51·6 (41·0–64·9) | 53·7 (43·8–65·9) | 49·7 (44·8–55·2) |
| Median | 45·3 | 45·3 | 45·3 | 45·3 | 45·3 |
| Seroprotection* | 183 (89·3%) | 190 (92·7%) | 180 (88·2%) | 184 (89·3%) | 737 (89·9%) |
| Post-second vaccination visit 3 (exploratory) | |||||
| Mean (GMT) | 1495·4 (1146·6–1950·4) | 1317·3 (1031·4–1682·6) | 646·2 (496·4–841·1) | 2209·1 (1752·1–2785·3) | NA |
| Median | 2048·0 | 1448·2 | 724·1 | 2896·3 | NA |
| Seroprotection* | 205 (100%) | 205 (100%) | 204 (100%) | 206 (100%) | NA |
| Seroconversion (primary outcome)† | 168 (82·0%) | 173 (84·4%) | 153 (75·0%) | 181 (87·9%) | NA |
| Seroconversion‡ | 168 (82·0%) | 173 (84·4%) | 153 (75·0%) | 181 (87·9%) | NA |
| Post-third vaccination visit 4 | |||||
| Mean (GMT) | 4495·1 (3726·5–5422·3) | 3151·8 (2575·2–3857·4) | 2410·8 (1956·3–2970·9) | 3759·2 (3224·3–4382·8) | NA |
| Median | 4096·0 | 4096·0 | 2896·3 | 4096·0 | NA |
| Seroprotection* | 205 (100%) | 205 (100%) | 204 (100%) | 206 (100%) | NA |
| Seroconversion (primary outcome)† | 200 (97·6%) | 197 (96·1%) | 193 (94·6%) | 203 (98·5%) | NA |
| Seroconversion‡ | 200 (97·6%) | 197 (96·1%) | 193 (94·6%) | 203 (98·5%) | 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.