TABLE 5.
Baseline characteristics of SARS-CoV-2 unexposed entire cohort corresponding to T2 non-seroconverted kidney transplant recipients and the boostered cohort corresponding to three vaccine dose kidney transplant recipients.
| Variable | Category | Entire cohort | Boostered cohort |
| Number | Evaluable | 193 | 166 |
| Age (years) | Mean ± SD | 58 ± 13.6 | 58.4 ± 13.5 |
| Male sex | n/% | 128/66.3 | 117/70.5 |
| BMI (kg/m2) | mean ± SD | 25.9 ± 5 | 26 ± 4.9 |
| Cause of end stage renal disease | n/% | 116/60.1 | 99/59.6 |
| Diabetes-Hypertension-Vascular disease | n/% | 35/18.1 | 32/19.3 |
| Glomerulonephritis-Interstitial nephritis | n/% | 49/25.4 | 41/24.7 |
| Vasculitis | n/% | 7/3.6 | 6/3.6 |
| Polycystic kidney disease | n/% | 25/13 | 20/12 |
| Unknown | n/% | 77/39.9 | 67/40.4 |
| Drug treated comorbidities | n/% | 176/91.2 | 149/89.8 |
| Diabetes mellitus | n/% | 35/18.1 | 32/19.3 |
| Cardiovascular disease | n/% | 170/88.1 | 143/86.1 |
| Lung disease | n/% | 15/7.8 | 11/6.6 |
| Liver cirrhosis | n/% | 3/1.6 | 3/1.8 |
| Cancer | n/% | 5/2.6 | 3/1.8 |
| None | n/% | 17/8.8 | 17/10.2 |
| Time on dialysis (years) | Mean ± SD | 6.1 ± 6.2 | 6.3 ± 6.3 |
| Time on transplantation (years) | Mean ± SD | 8.5 ± 6.3 | 8.2 ± 6.1 |
| Previous transplantation | n/% | 28/14.5 | 23/13.9 |
| Hepatitis B vaccination failure | n/% | 10/5.2 | 9/5.4 |
| Flu vaccination winter 2020/2021 | n/% | 106/54.9 | 90/54.2 |
| On immunosuppressive therapy | n/% | 193/100 | 166/100 |
| Corticosteroids | n/% | 91/47.2 | 78/47 |
| Calcineurin-inhibitor | n/% | 179/92.7 | 154/92.8 |
| MMF/MPA | n/% | 170/88.1 | 146/88 |
| mTOR-Inhibitor | n/% | 22/11.4 | 18/10.8 |
| Belatacept | n/% | 14/7.3 | 12/7.2 |
| T-cell depleting ab | n/% | 0/0 | 0/0 |
| B-cell depleting ab n | n/% | 1/0.5 | 1/0.6 |
| Other | n/% | 2/1 | 2/1.2 |
| Type of vaccine | |||
| BNT162b2-mRNA | n/% | 87/45.1 | 83/50 |
| 1273-mRNA | n/% | 106/54.9 | 83/50 |
The entire cohort consists of non-responding KTR after two mRNA vaccinations. Boostered cohort consists of non-responding KTR after two mRNA vaccinations who received the third vaccination.
For this evaluation, all patients with asymptomatic* or documented symptomatic** COVID-19 disease before and during vaccination up to T3 (6 months) were excluded.
Hepatitis B vaccination failure definition–patients with unsuccessful vaccination after at least four attempts; MMF-MPA, mycophenolate mofetil or mycophenolic acid.
*Asymptomatic COVID-19 disease definition–neither knowledge nor symptoms of COVID-19 disease, but IgG-antibody reaction to nucleocapsid (T0, T1, T2, or T3) or 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.