Table 3.
Results of 2009 pandemic influenza A (H1N1) antibodies before and after the pandemic in 60 vaccinated and 90 unvaccinated health care workers at a children's hospital in Taiwan
| All (N = 150) | Vaccinated (N = 60) No. (%) |
Unvaccinated (N = 90) | ||||
|---|---|---|---|---|---|---|
| All No. (%) |
High-risk (N = 40)3 No. (%) |
Low-risk (N = 50)3 No. (%) |
P value1 | |||
| Seroprotective | ||||||
| Baseline2 | 7 (4.7%) | 2 (3.3%) | 5 (5.6%) | 3 (7.5%) | 2 (4.0%) | 0.652 |
| Second2 | 13 (8.7%) | 2 (3.3%) | 11 (12.2%) | 8 (20.0%) | 3 (6.0%) | 0.056 |
| Third2 | 52 (35.4%) | 34 (56.7%) | 18 (20.0%) | 12 (30.0%) | 6(12.0%) | 0.061 |
| Seroconversion | ||||||
| 1st to 2nd sera | 6 (4.0%) | 0 (0.0%) | 6 (6.7%) | 5 (12.5%) | 1 (2.0%) | 0.085 |
| 2nd to 3 rd sera | 39 (26.5%) | 32 (53%) | 7 (7.8%) | 4 (10.0%) | 3 (6.0%) | 0.695 |
| 1st to 3 rd sera | 45 (30.6%) | 32 (53%) | 13 (14.4%) | 9 (22.5%) | 4 (8.0%) | 0.071 |
| GMT (95% CI) | ||||||
| Base line | 11.0 (10.7-12.0%) | 11.0 (10.5-12.6) | 11.2 (10.4-12.1) | 12.1 (10.5-13.9) | 10.6 (9.7-11.5) | 0.049 |
| Second | 12.4 (11.4-13.6%) | 11.4 (10.4-12.4) | 13.2 (11.5-15.1) | 16.0 (12.6-20.3) | 11.3 (9.9-12.9) | 0.013 |
| Third | 19.2 (16.6-22.1%) | 31.4 (23.8-36.8) | 14.0 (12.0-16.3) | 18.3 (14.0-24.1) | 11.3 (9.8-13.1) | 0.003 |
Abbreviations: GMT: geometric mean titer; CI: confidence interval.
1 Comparisons were made between high- and normal-risk groups, using Chi-square or Fisher exact tests.
2 See text and Figure 2 for definitions of baseline, second, and third samples.
3 See text for definitions of high- and low-risk.