Table 4.
Characterization of vaccinated and naive to infection individuals who respond to the post-12-month questionnaire
| Characteristics | All post-12-months | Not infected post-12-months | Infected post-12-months | p-value1 | |
|---|---|---|---|---|---|
| Univariable | Multivariable | ||||
| n | 169 | 134 | 35 | ||
| M/F | 32/137 | 27/107 | 5/30 | 0.6 | |
| Age (years), median (IQR) | 50 (42; 57) | 52 (43; 58) | 44 (35; 52) | 0.0026 | 0.0084 |
| BMI (ratio), median (IQR) | 23.5 (21.7; 27) | 23.6 (21.7; 27.1) | 23.3 (21.2; 26.2) | 0.63 | |
| Comorbidities (n, %) | 67 (39.6%) | 55 (41%) | 12 (34.3%) | 0.6 | |
| HCWs (n, %) | 38 (22.5%) | 26 (19.4%) | 12 (34.3%) | 0.07 | 0.25 |
| Time between last dose and questionnaire (days), median (IQR) | – | 96 (75.5; 107.3) | 74 (39; 130) | 0.0001 | 0.14 |
| Time between vaccination and sampling (days), median (IQR) | 181 (144; 224) | 181.5 (144; 223.3) | 180 (139; 238) | 0.95 | |
| Number of vaccine doses before sampling (n, %) | 2 (169, 100%) | 2 (134, 100%) | 2 (35, 100%) | – | |
| Current number of vaccine doses (n, %) | – | 3 (126, 94%) | 3 (22, 62.9%) | < 0.0001 | 0.28 |
| Anti-SP IgG (BAU/mL), median (IQR) | 147 (70; 320.5) | 149.5 (70.8; 331) | 129 (62; 259) | 0.5 | |
| Neutralization of Wuhan variant, median (IQR) | 3.9 (1.9; 7.9) | 4.1 (2; 7.9) | 3.8 (1.7; 7) | 0.7 | |
| Neutralization of Alpha variant, median (IQR) | 3.3 (1.5; 6) | 3.4 (1.5; 6.2) | 3.2 (1.5; 5.4) | 0.7 | |
| Neutralization of Delta variant, median (IQR) | 3.1 (1.6; 6.4) | 3 (1.5; 6.5) | 3.5 (1.8; 5.4) | 0.9 | |
| SARS-CoV-2 specific T cell response (IU/mL), median (IQR) | 0.23 (0.1; 0.53) | 0.25 (0.12; 0.58) | 0.15 (0.08; 0.32) | 0.06 | 0.04 |
N number; IQR interquartile range; HCW health care workers; Anti-SP anti-Spike; IgG immunoglobulin G; Anti-N anti-nucleocapsid
*p < 0.05, **p < 0.005, ***p < 0.0005, ****p < 0.00005
1Mann-Whitney test for quantitative variables; Fisher’s exact test for qualitative variables. All tests are two-sided with statistical significance p < 0.05. To identify infection and bad vaccine responder’s predictive factors, all variables with p < 0.15 in unadjusted analysis were used for multivariable logistic regression models