Table 2.
Overall Glycoprotein Enzyme-Linked Immunosorbent Assay and Plaque Reduction Neutralization Test Results at Baseline and 1, 6, and 9–12 Months After Vaccination with Recombinant Vesicular Stomatitis Virus–Zaire Ebola Virus Envelope Glycoprotein Vaccine, in the Immunogenicity Substudy of the Sierra Leone Trial to Introduce a Vaccine Against Ebola (STRIVE)
| Test and Result |
Time Point | ||||
|---|---|---|---|---|---|
| Baseline | mo 1 | mo 6 | mo 9–12 | Any Time After Vaccination | |
| GP-ELISA (N = 506)a | |||||
| Participants in GMT analysis, no. | 503 | 443 | 383 | 393 | NA |
| GMT (95% CI) | 92.7 (85.3–100.9) |
964.3 (878.7–1058.3) |
751.8 (690.6–818.4) |
760.8 (697.6–829.8) |
|
| Participants in GMFR analysis, no. | NA | 441 | 381 | 393 | NA |
| GMFR (95% CI) | 10.7 (9.6–12.0) |
8.1 (7.3–9.1) |
8.4 (7.5–9.4) |
||
| Seroresponders/participants in 1st seroresponse analysis, no. | NA | 397/441 | 341/381 | 345/393 | 446/474 |
| Seroresponse ≥2-fold increase from baseline and ≥200 EU/mL,% (95% CI) |
90.0 (86.8–92.7) |
89.5 (86.0–92.4) |
87.8 (84.1–90.9) |
94.1 (91.6–96.0) |
|
| Seroresponders/participants in 2nd seroresponse analysis, no. | NA | 352/441 | 295/381 | 292/393 | 414/474 |
| Seroresponse ≥4-fold increase from baseline, % (95% CI) | 79.8 (75.8–83.5) |
77.4 (72.9–81.5) |
74.3 (69.7–78.6) |
87.3 (84.0–92.0) |
|
| PRNT (N = 504)a | |||||
| Participants in GMT analysis, no. | 438 | 437 | 382 | 396 | NA |
| GMT (95% CI) | <35 (<35 to <35) |
116.0 (105.7–127.4) |
95.3 (86.3–105.3) |
119.9 (107.9–133.2) |
|
| Participants in GMFR analysis, no. | NA | 376 | 326 | 342 | NA |
| GMFR (95% CI) | 6.3 (5.7–7.0) |
5.4 (4.8–6.0) |
6.8 (6.1–7.6) |
||
| Seroresponders/participants in seroresponse analysis, no. | NA | 265/376 | 211/326 | 237/342 | 334/410 |
| Seroresponse ≥4-fold increase from baseline, % (95% CI) | 70.5 (65.6–75.0) |
64.7 (59.3–69.9) |
69.3 (64.1–74.1) |
81.5 (77.4–85.1) |
Abbreviations: CI, confidence interval; EU, enzyme-linked immunosorbent assay units; GMFR, geometric mean fold rise; GMT, geometric mean titer; GP-ELISA, glycoprotein enzyme-linked immunosorbent assay; NA, not applicable; PRNT, plaque reduction neutralization test.
aNumber of participants with serology data at ≥1 time point according to the study group to which they were randomized.