Immunogenicity of influenza vaccine
| MTX continue (n=156) | MTX hold (n=160) | P values | |
| H1N1 | |||
| Pre-vacc titre, GMT (95% CI) | 14.8 (12.7 to 17.3) | 16.2 (13.9 to 18.9) | 0.422 |
| Post-vacc titre, GMT (95% CI) | 68.4 (56.8 to 82.4) | 108.4 (90.7 to 129.5) | 0.001 |
| Fold increase, GM (95% CI) | 4.6 (3.7 to 5.7) | 6.7 (5.4 to 8.3) | 0.018 |
| Response, n (%) | 79 (50.6) | 100 (62.5) | 0.033 |
| Pre-vacc SP, n (%) | 38 (24.4) | 46 (28.8) | 0.377 |
| Post-vacc SP, n (%) | 118 (75.6) | 138 (86.3) | 0.016 |
| H3N2 | |||
| Pre-vacc titre, GMT (95% CI) | 10.2 (8.8 to 11.8) | 10.6 (9.1 to 12.3) | 0.695 |
| Post-vacc titre, GMT (95% CI) | 43.9 (36.1 to 53.4) | 84.3 (69.3 to 102.4) | <0.001 |
| Fold increase, GM (95% CI) | 4.3 (3.5 to 5.3) | 8.0 (6.4 to 9.9) | <0.001 |
| Response, n (%) | 85 (54.5) | 114 (71.3) | <0.001 |
| Pre-vacc SP, n (%) | 21 (13.5) | 21 (13.1) | 0.930 |
| Post-vacc SP, n (%) | 97 (62.2) | 125 (78.1) | 0.002 |
| B-Yamagata | |||
| Pre-vacc titre, GMT (95% CI) | 22.4 (18.7 to 26.7) | 20.8 (18.1– to 4.0) | 0.534 |
| Post-vacc titre, GMT (95% CI) | 70.4 (57.8 to 85.7) | 115.6 (97.4 to 137.3) | <0.001 |
| Fold increase, GM (95% CI) | 3.1 (2.6 to 3.8) | 5.6 (4.7 to 6.6) | <0.001 |
| Response, n (%) | 66 (42.3) | 104 (65.0) | <0.001 |
| Pre-vacc SP, n (%) | 60 (38.5) | 51 (31.9) | 0.220 |
| Post-vacc SP, n (%) | 116 (74.4) | 141 (88.1) | 0.002 |
| B-Victoria | |||
| Pre-vacc titre, GMT (95% CI) | 13.8 (12.1 to 15.8) | 11.7 (10.3 to 13.2) | 0.065 |
| Post-vacc titre, GMT (95% CI) | 39.5 (33.3 to 46.9) | 66.3 (56.8 to 77.4) | <0.001 |
| Fold increase, GM (95% CI) | 2.9 (2.4 to 3.4) | 5.7 (4.9 to 6.7) | <0.001 |
| Response, n (%) | 64 (41.0) | 118 (73.8) | <0.001 |
| Pre-vacc SP, n (%) | 33 (21.2) | 21 (13.1) | 0.058 |
| Post-vacc SP, n (%) | 95 (60.9) | 121 (75.6) | 0.005 |
Data are expressed in n (%) or value (95% CI). Antibody titres and fold increase are in GMT. Satisfactory vaccine response (ie, response=seroconversion) was defined as greater than or equal to fourfold improvement in titres relative to baseline. Seroprotection was defined as titres of ≥1:40. P values were generated by independent t-test for continuous variables and Χ2 test for categorical variables.
Antibody titres, fold changes and vaccine response before and after vaccination to individual vaccine strains.
GM, geometric mean; GMT, geometric mean titre; n, number; pre-vacc SP, prevaccination seroprotection rate; post-vacc SP, postvaccination seroprotection rate.