Table 2. Factors which may influence risk for reinfection in volunteers.
| Explanatory variable | N | n (%) | Odds ratio of each factor for reinfection |
|||
|---|---|---|---|---|---|---|
| Crude | [95% CI] | Adjusteda | [95% CI] | |||
| Response to BK-SE36 vaccination (based on ≥1.92-fold increase at Day 42) | ||||||
| Responder | 11 | 2 (18) | 0.2 | [0.03, 0.8] | 0.1 | [0.01, 0.5] |
| Non responder | 26 | 12 (46) | 0.7 | [0.3, 1.9] | 0.7 | [0.3, 2.2] |
| Placebo, Control | 40 | 22 (55) | 1.0 | 1.0 | ||
| Age (yr) | ||||||
| 6–10 | 30 | 17 (57) | 1.0 | 1.0 | ||
| 11–20 | 47 | 19 (40) | 0.5 | [0.2, 1.3] | 0.3 | [0.1, 1.03] |
| Anti-SE36 antibody titre after first infection (based on median arbitrary unit) | ||||||
| ≤80.0 | 39 | 17 (44) | 1.0 | 1.0 | ||
| >80.0 | 38 | 19 (50) | 1.3 | [0.5, 3.2] | 1.9 | [0.7, 5.5] |
| Parasitemia during the first infection (parasites/μl) | ||||||
| <5,000 | 41 | 18 (44) | 1.0 | 1.0 | ||
| ≥5,000 | 36 | 18 (50) | 1.3 | [0.5, 3.2] | 1.1 | [0.4, 3.1] |
Significant results are shown in bold. N, sample size; n (%), frequency of volunteers with >1 infection during 130–365 days post-second vaccination; CI, confidence interval.
aAll variables shown in the table are adjusted simultaneously using the multivariate logistic regression.