Table 1.
Demographic and immunological variables of the study subjects.
| Variable | Non-responders (N = 58) |
Respondersa (N = 36) |
Overall (N = 94) |
|---|---|---|---|
| Age, years, median (IQRb) | 59.7 (55.9; 69.0) | 59.7 (55.0; 63.8) | 59.7 (55.4; 67.0) |
| Gender (n, %) |
|||
| Female | 37 (63.8) | 20 (55.6) | 57 (60.6) |
| Male | 21 (36.2) | 16 (44.4) | 37 (39.4) |
| Race (n, %) |
|||
| Caucasians | 57 (98.3) | 36 (100.0) | 93 (98.9) |
| Others | 1 (1.7) | 0 (0.0) | 1 (1.1) |
| HAI titer, median (IQRb) |
|||
| Day 0 | 1:160 (1:80, 1:160) | 1:80 (1:40, 1:80) | 1:80 (1:40, 1:160) |
| Day 3 | 1:160 (1:80, 1:160) | 1:80 (1:40, 1:160) | 1:80 (1:50, 1:160) |
| Day 28 | 1:160 (1:80, 1:320) | 1:320 (1:280, 1:1280) | 1:320 (1:80, 1:320) |
a
At least four-fold increase in the antibody titers between the pre-vaccination and the Day 28 sample. bIQR, interquartile range.