Table 4.
Hemagglutination inhibition (HI) antibody titers 4 weeks post-vaccination by baseline seronegative and seropositive status in the intradermal (ID) group (total n = 75) compared to intramuscular (IM) group (total n = 74).
| Seronegative (HI titers < 1:10) |
Seropositive (HI titers > 1:10) |
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| H1N1pdm09 |
H3N2 |
B |
H1N1pdm09 |
H3N2 |
B |
||||||||||
| CPMPAge> 60 yrs | ID n = 36 | IM n = 36 | ID n = 14 | IM n = 18 | ID n = 51 | IM n = 51 | ID n = 39 | IM n = 38 | ID n = 61 | IM n = 56 | ID n = 24 | IM n = 23 | |||
| Pre-vaccination GMT (95% CI) | 5 | 5 | 5 | 5 | 5 | 5 | 35.3(23.8-52.5) | 32.1(23.7-43.6) | 45.8(33.5-62.8) | 44.2(31.7-61.6) | 38.9(25.6-59.0) | 32.4(22.0-47.7) | |||
| P-value | 0.892 | 0.881 | 0.566 | ||||||||||||
| Post-vaccination GMT(95% CI) | 37.0 (23.0-59.7) | 52.4 (31.4-87.4) | 97.5 (40.4-235.1) | 74.1 (34.5-159.2) | 15.9 (11.8-21.3) | 14.6 (10.4-20.6) | 127.0(80.9-199.2) | 175.3(122.8-250.2) | 179.3(128.0-251.1) | 174.5(122.5-248.6) | 51.9(27.9-96.6) | 41.2(23.0-73.8) | |||
| P-value | 0.325 | 0.604 | 0.400 | 0.410 | 0.900 | 0.493 | |||||||||
| Seroconversion factor (95% CI) | > 2.0 | 17.6(10.3-24.8) | 29.2 (15.3-43.1) | 44.9 (16.3-73.4) | 37.3 (14.4-60.2) | 5.7(3.7-7.8) | 6.8(3.9-9.6) | 9.0(4.9-13.1) | 11.0(6.9-15.1) | 9.8(6.6-13.1) | 10.6 (6.7-14.8) | 2.2(1.2-3.1) | 3.3(0.3-6.4) | ||
| P-value | 0.325 | 0.604 | 0.400 | 0.162 | 0.886 | 0.630 | |||||||||
| Seroconversion rate %, (95% CI) | > 30 | 47.2 (32.0-63.0) | 61.1 (44.8-75.2) | 71.4 (45.0-88.7) | 66.7 (43.5-83.9) | 27.5 (17.0-41.0) | 27.5 (17.0-41.0) | 53.8 (38.6-68.4) | 71.1 (55.1-83.1) | 57.4 (44.9-69.0) | 51.8 (39.0-64.3) | 25.0 (11.7-45.2) | 17.4 (6.3-37.7) | ||
| P-value | 0.237 | 0.773 | 1.000 | 0.119 | 0.544 | 0.524 | |||||||||
| Pre-vaccination seroprotection rate%, (95% CI) | 0 | 0 | 0 | 0 | 0 | 0 | 46.2 (31.6-61.4) | 55.3 (39.7-69.9) | 62.3(49.7-73.4) | 53.6(40.7-66.0) | 54.2(35.1-72.1) | 47.8 (29.2-67.0) | |||
| P-value | 0.424 | 0.339 | 0.664 | ||||||||||||
| Post-vaccination seroprotection rate%, (95% CI) | > 60 | 47.2 (32.0-63.0) | 61.1 (44.8-75.2) | 71.4 (45.0-88.7) | 66.7 (43.6-83.9) | 27.5 (17.0-41.0) | 27.5 (17.0-41.0) | 79.5 (64.2-89.5) | 94.7 (81.8-99.5) | 83.6 (72.2-91.0) | 83.9 (72.0-91.5) | 70.8 (50.6-85.3) | 56.5 (36.8-74.4) | ||
| P-value | 0.237 | 0.773 | 1.000 | 0.047* | 0.962 | 0.307 | |||||||||
*
The level of critical significance was assigned at p < 0.05.