TABLE 1.
Factors associated with response to mRNA-based vaccines
| Total (n = 91) |
Seroconversion (n = 57) |
No seroconversion (n = 34) |
p | |
|---|---|---|---|---|
| Vaccine type, n (mRNA-1273/BNT162b2) | 84/7 | 56/1 | 28/6 | |
| Antibody titer U/ml, median [IQR] | 20.5 [1.5–95] | 63.9 [27.1–268.7] | 0.72 [0.2–2.8] | <.001 |
| Male gender, n (%) | 61 (67) | 42 (73.7) | 19 (55.9) | .091 |
| Age, median [IQR] | 59 [51–66] | 59 [50–64.5] | 62.5 [58–70.5] | .022 |
| Age ≥65 years, n (%)a | 30 (33) | 14 (46.7) | 16 (53.3) | .027 |
| Time from KT to COVID-19 vaccine (months), median [IQR] | 64 [22–158] | 96 [41–187] | 27.5 [17.5–110.7] | .004 |
| Thymoglobulin, n (%)b | 5 (5.5) | 2 (3.5) | 3 (8.8) | .282 |
| Rituximabb | 1 (1.1) | 0 | 1 (2.9) | .193 |
| Prednisone, n (%) | 87 (95.6) | 53 (93) | 34 (100) | .114 |
| Tacrolimus, n (%) | 84 (92.3) | 51 (89.5) | 33 (97.1) | .189 |
| MPA, n (%) | 76 (83.5) | 44 (77.2) | 32 (94.1) | .035 |
| mTOR inhibitors, n (%) | 10 (11) | 8 (14) | 2 (5.9) | .229 |
| Azathioprine, n (%) | 2 (2.2) | 1 (1.8) | 1 (2.9) | .709 |
| AR episode, n (%)b | 3 (3.5) | 2 (3.6) | 1 (3.2) | .921 |
| Serum creatinine, median [IQR] | 1.3 [1.1–1.6] | 1.2 [0.9–1.5] | 1.4 [1.3–1.8] | .002 |
| Multiple logistic regression analysis for seroconversion | ||
|---|---|---|
| OR (95% CI) | p | |
| Recipient age | 0.94 (0.89–0.99) | .024 |
| Time from KT to COVID-19 vaccine | 1.00 (1.00–1.01) | .011 |
| Serum creatinine | 0.28 (0.12–0.68) | .005 |
| MPA | 0.08 (0.01–0.53) | .008 |
Abbreviations: CI, confidence interval; IQR, interquartile range; MPA, mycophenolic acid; OR, odds ratio.
a
Percentage within age < or ≥65 years.
b
In the last year prior to COVID-19 vaccine.