Table 2.
Hemagglutination inhibition (HI) antibody titers in the intradermal (ID) group (n = 75) compared with intramuscular (IM) group (n = 74) pre-vaccination and 4 weeks post-vaccination.
| H1N1pdm09 |
H3N2 |
B |
|||||
|---|---|---|---|---|---|---|---|
| CPMP Age > 60 yrs | ID | IM | ID | IM | ID | IM | |
| Pre-vaccination GMT (95% CI) | 13.8(10.2 – 18.7) | 13.0(10.0-17.0) | 30.3(21.9-41.9) | 26.0(18.7-36.2) | 9.6(7.5-12.4) | 8.9(7.1-11.3) | |
| P-value | 0.984 | 0.479 | 0.812 | ||||
| Post-vaccination GMT(95% CI) | 70.3(49.5– 99.8) | 97.4(69.8-135.8) | 160.0(116.8-219.2) | 141.7(102.0-196.7) | 23.2(17.2-31.3) | 20.2(14.8-27.5) | |
| P-value | 0.192 | 0.601 | 0.449 | ||||
| Seroconversion factor (95% CI) | > 2.0 | 13.1(9.0-17.2) | 19.9(12.7-27.1) | 16.4(10.1-22.7) | 17.2(10.7-23.8) | 4.6(3.1-6.1) | 5.7(3.5-7.8) |
| P-value | 0.113 | 0.971 | 0.371 | ||||
| Seroconversion rate %, (95% CI) | > 30 | 50.7(39.6-61.7) | 66.2(54.8-76.0) | 60.0(48.7-70.3) | 55.4(44.1-66.2) | 26.7(18.0-37.7) | 24.3(15.9-35.3) |
| P-value | 0.054 | 0.570 | 0.743 | ||||
| Pre-vaccination seroprotection rate%, (95% CI) | 24.0(15.7-34.9) | 28.4(19.3-39.6) | 50.7(39.6-61.7) | 40.5(30.1-52.0) | 17.3(10.3-27.6) | 14.9(8.3-24.9) | |
| P-value | 0.543 | 0.215 | 0.682 | ||||
| Post-vaccination seroprotection rate%, (95% CI) | > 60 | 64.0(52.7-74.0) | 78.4(67.6-86.3) | 81.3(71.0-88.7) | 79.7(69.1-87.4) | 41.3(30.9-52.6) | 36.5(26.4-47.9) |
| P-value | 0.053 | 0.805 | 0.544 | ||||
CPMP = Committee for Proprietary Medicinal Products.4
GMT = Geometric mean titers.
Seroconversion factor = the ratio of the HI titer after vaccination to the HI titer before vaccination.
Seroconversion rate = the percentage of post-vaccination HI titer ≥ 1:40 in patients with pre-vaccination titer < 1:10 or ≥ 4-fold increase in post-vaccination HI titer in patients with a pre-vaccination titer ≥ 1:10.
Seroprotection rate = the percentage of patients with post-vaccination HI titer ≥ 1:40.