Table 2.
Immune response rates six months after vaccination (T3) in the seroconverted pure vaccination cohort.
| Variable | Category | Medical personnel | Dialysis patients | Kidney transplant recipients | p-value(chi-squared test) |
|---|---|---|---|---|---|
| Patient number | n | 125 | 970 | 110 | |
| Humoral responses | n of total n (%) | ||||
| IgG-Ab or IgA-Ab Spike S1 positive | n of total n (%) | 123 / 125 (98·4%) | 879 / 970 (90·6%) | 96 / 110 (87·3%) | 0·005 |
| IgA-Ab Spike S1 positive | n of total n (%) | 96 / 125 (76·8%) | 537 / 938 (57·2%) | 65 / 110 (59·1%) | < 0·001 |
| IgA-Ab Spike S1 increasing | n of total n (%) | 1 / 125 (0·8%) | 20 / 970 (2·1%) | 4 / 110 (3·6%) | 0·313 |
| IgA-Ab Spike S1 equal | n of total n (%) | 2 / 125 (1·6%) | 11 / 970 (1·1%) | 2 / 110 (1·8%) | 0·771 |
| IgA-Ab Spike S1 decreasing | n of total n (%) | 122 / 125 (97·6%) | 939 / 970 (96·8%) | 104 / 110 (94·5%) | 0·379 |
| De novo IgA-Ab positivity (T2 negative, T3 positive) | n of total n (%) | 0 / 125 (0%) | 5 / 970 (0·5%) | 2 / 110 (1·8%) | 0·156 |
| IgG-Ab Spike S1 positive | n of total n (%) | 123 / 125 (98·4%) | 865 / 970 (89·2%) | 92 / 110 (83·6%) | 0·001 |
| IgG-Ab Spike S1 increasing | n of total n (%) | 0 / 125 (0%) | 13 / 970 (1·3%) | 17 / 110 (15·5%) | < 0·001 |
| IgG-Ab Spike S1 equal | n of total n (%) | 74 / 125 (59·2%) | 297 / 970 (30·6%) | 30 / 110 (27·3%) | < 0·001 |
| IgG-Ab Spike S1 decreasing | n of total n (%) | 51 / 125 (40·8%) | 660 / 970 (68%) | 63 / 110 (57·3%) | < 0·001 |
| De novo IgG-Ab positivity (T2 negative, T3 positive) | n of total n (%) | 0 / 125 (0%) | 1 / 970 (0·1%) | 3 / 110 (2·7%) | < 0·001 |
| RBD positive | n of total n (%) | 122 / 125 (97·6%) | 656 / 970 (67·6%) | 63 / 110 (57·3%) | < 0·001 |
| RBD increasing | n of total n (%) | 0 / 116 (0%) | 7 / 908 (0·8%) | 12 / 104 (11·5%) | < 0·001 |
| RBD equal | n of total n (%) | 88 / 116 (75·9%) | 282 / 908 (31·1%) | 35 / 104 (33·7%) | < 0·001 |
| RBD decreasing | n of total n (%) | 28 / 116 (24·1%) | 619 / 908 (68·2%) | 57 / 104 (54·8%) | < 0·001 |
| De novo RBD positive (T2 negative, T3 positive) |
n of total n (%) | 0 / 116 (0%) | 3 / 908 (0·3%) | 6 / 104 (5·8%) | < 0·001 |
| Interferon-γ release assay (IGRA)– T-cellular response | |||||
| IGRA positive | n of total n (%) | 22 / 28 (78·6%) | 72 / 116 (62·1%) | 15 / 41 (36·6%) | 0·001 |
| IGRA increasing | n of total n (%) | 1 / 29 (3·4%) | 7 / 102 (6·9%) | 12 / 34 (35·3%) | < 0·001 |
| IGRA equal | n of total n (%) | 10 / 29 (34·5 %) | 33 / 102 (32·4%%) | 1 / 34 (2·9%) | 0·002 |
| IGRA decreasing | n of total n (%) | 18 / 29 (62·1%) | 62 / 102 (60·8%) | 21 / 34 (61·8%) | 0·989 |
| De novo positivity for IGRA | n of total n (%) | 0 / 29 (0%) | 2 / 102 (2%) | 2 / 34 (5·9%) | 0·282 |
MP = Medical Personnel; DP = Dialysis Patients; KTR = Kidney Transplant Recipient; Interferon-γ release assay = IGRA;
Humoral vaccination responses were assessed as positive, when de novo production of the antibody to the Spike S1 (IgA or IgG) protein or RBD (IgG) subunit was above positivity level. A positive T-cellular response to vaccination as assessed by interferon-γ release assay (IGRA) turned from a negative result on T0 to positive on T3, respectively (≥100 mIU/ml, as being recommended by the manufactures). Using 20% as a margin, the time course of antibody or IGRA titres at T3 compared to T2 time point were categorized into increased (> 20%), equal (within 20% range), and decreased (< 20%). For this evaluation, all participants with asymptomatic* or documented symptomatic** COVID-19 disease before and during vaccination up to T3 (six months) were excluded.
*Asymptomatic COVID-19 disease definition - neither knowledge nor symptoms of COVID-19 disease, but IgG-antibody reaction to nucleocapsid (T0, T2 or T3) or to the Spike protein subunit S1 (only T0) of the SARS-CoV-2 virus is positive.
**Symptomatic COVID-19 disease definition - SARS-CoV-2 PCR positive patients with clinical symptoms.