Table 1. Linear regression showing the predictor neutralizing antibody anti-SRBD titre post-vaccination (n = 115).
| Characteristic | n (%) | Mean concentration (±SD), IU/mL | Initial model | Final model | ||
|---|---|---|---|---|---|---|
| ß (95% CI) | p–value | ß (95% CI) | p–value | |||
| Post-vaccination time (month) | ||||||
| 1 (Reference, R) | 16 (13.9) | 184.6 (±79.9) | ||||
| 2 | 10 (8.7) | 180.1 (±81.9) | 12.9 (-75.1, 100.9) | 0.771 | 9.8 (-65.7, 85.3) | 0.797 |
| 3 | 6 (5.2) | 95.6 (±89.0) | -57.5 (-159.1, 44.0) | 0.263 | -99.8 (-188.6, -11.1) | 0.028 |
| 4 | 7 (6.1) | 127.0 (±103.5) | -49.9 (-146.1, 46.3) | 0.305 | -50.6 (-134.1, 32.9) | 0.232 |
| 5 | 38 (33.0) | 101.8 (±102.2) | -70.3 (-134.9, -5.7) | 0.033 | -74.3 (-129.5, -19.1) | 0.009 |
| 6 | 38 (33.0) | 95.6 (±95.2) | -96.2 (-155.8, -36.7) | 0.002 | -93.3 (-148.2, -38.4) | 0.001 |
| Age (year) | ||||||
| 20-30 (R) | 59 (51.3) | 122.0 (±93.7) | ||||
| 31-40 | 32 (27.8) | 127.3 (±109.5) | 3.5 (-49.4, 56.3) | 0.896 | ||
| 41-50 | 16 (13.9) | 117.5 (±108.4) | -4.9 (-70.4, 60.7) | 0.883 | ||
| >50 | 8 (7.0) | 71.0 (±80.6) | -6.5(-100.3, 87.4) | 0.892 | ||
| Gender | ||||||
| Male (R) | 38 (33.0) | 121.9 (±102.2) | ||||
| Female | 77 (67.0) | 118.0 (±98.4) | -34.3 (-83.8, 15.2) | 0.172 | ||
| Body mass index (BMI) | ||||||
| Underweight (R) | 11 (9.6) | 102.0 (±99.1) | ||||
| Normal | 35 (30.4) | 125.8 (±96.4) | 13.9 (-57.1, 85.0) | 0.698 | ||
| Overweight | 26 (22.6) | 103.2 (±99.2) | 12.3 (-64.2, 88.9) | 0.750 | ||
| Obesity | 43 (37.4) | 128.2 (±103.4) | 24.5 (-47.3, 96.3) | 0.500 | ||
| Regular exercise | ||||||
| Yes | 32 (27.8) | 103.2 (±98.3) | 2.2 (-47.7, 52.1) | 0.930 | ||
| No (R) | 83 (72.2) | 125.5 (±99.5) | ||||
| Sleep quality | ||||||
| Good | 40 (34.8) | 98.1 (±95.1) | -45.5 (-87.6, -3.4) | 0.035 | -30.0 (-66.6, 6.6) | 0.107 |
| Poor (R) | 75 (65.2) | 130.6 (±100.2) | ||||
| Healthy meal | ||||||
| No | 76 (66.1) | 110.4 (±98.8) | -46.7 (-93.4, 0.1) | 0.050 | -39.2 (-77.3, -1.0) | 0.044 |
| Yes (R) | 39 (33.9) | 136.7 (±99.2) | ||||
| Regular food supplementation | ||||||
| Yes | 65 (56.5) | 116.6 (±98.5) | 15.3 (-25.2, 55.8) | 0.454 | ||
| No (R) | 50 (43.5) | 122.8(±101.1) | ||||
| Smoking | ||||||
| Yes (R) | 10 (8.7) | 100.1 (±107.1) | ||||
| No | 105 (91.3) | 121.1 (±98.9) | 20.4 (-63.4, 104.2) | 0.630 | ||
| Stress level | ||||||
| Normal (R) | 96 (83.5) | 123.2 (±101.5) | ||||
| Mild | 5 (4.3) | 76.1 (±97.8) | -81.6 (-182.2, 18.9) | 0.110 | ||
| Moderate | 7 (6.1) | 88.6 (±74.0) | -66.8 (-153.7, 20.2) | 0.131 | ||
| Severe | 7 (6.1) | 126.8 (±96.4) | 1.75 (-77.0, 80.5) | 0.965 | ||
| Stress | ||||||
| Yes | 19 (16.5) | 99.4 (±86.8) | NA (NA, NA) | NA | ||
| No (R) | 96 (83.5) | 123.2 (±101.5) | ||||
| Comorbidity | ||||||
| Hypertension | ||||||
| Yes (R) | 6 (5.2) | 45.1 (±46.3) | ||||
| No | 109 (94.8) | 123.4 (±99.9) | 65.5 (-25.3, 156.3) | 0.155 | ||
| Hyperlipidaemia | ||||||
| Yes (R) | 8 (7.0) | 53.0 (±80.4) | ||||
| No | 107 (93.0) | 124.2 (±99.1) | 44.6 (-42.1, 131.3) | 0.309 | ||
| Gout | ||||||
| Yes (R) | 13 (11.3) | 103.9 (±94.1) | ||||
| No | 102 (88.7) | 121.2 (±100.2) | 35.1 (-39.6, 109.7) | 0.353 | ||
| History of infection except COVID-19 | ||||||
| Yes (R) | 15 (13.0) | 135.9 (±94.7) | 18.4 (-43.5, 80.3) | 0.556 | ||
| No | 100 (87.0) | 116.8 (±100.2) | ||||
| Experience of vaccination side effect | ||||||
| No (R) | 58 (50.4) | 118.2 (±98.8) | ||||
| Yes | 57 (49.6) | 120.4 (±100.7) | 4.9 (-36.7, 46.5) | 0.815 | ||
| History of flu vaccination | ||||||
| Yes | 24 (20.9) | 107.1 (±96.0) | -13.9 (-63.2, 35.4) | 0.577 | ||
| No (R) | 91 (79.1) | 122.5 (±100.4) | ||||