Table 5.
Rate of SARS-CoV-2 breakthrough infection and its severity according to SARS-CoV-2-reactive IgG antibody levels cut-off at 3–6 weeks, 3 months and 6 months after complete vaccination in the whole cohort and in allo-HSCT recipients.
| Variable | <250 BAU/mL At 3–6 weeks | ≥250 BAU/mL At 3–6 weeks | P value | <250 BAU/mL At 3 months | ≥250 BAU/mL At 3 months | P value | <250 BAU/mL At 6 months | ≥250 BAU/mL At 6 months | P value |
|---|---|---|---|---|---|---|---|---|---|
| Whole cohort | 149 | 282 | 125 | 265 | 91 | 233 | |||
| SARS-CoV-2 infection, n (%) | 29 (19) | 35 (12.4) | 0.06 | 21 (17) | 30 (11) | 0.1 | 20 (22) | 23 (9.8) | 0.006 |
| Symptomatic SARS-CoV-2 | 18/29 (62) | 15/35 (43) | 0.1 | 14/21 (66.7) | 12/30 (40) | 0.08 | 14/20 (70) | 10/23 (43) | 0.1 |
| Pneumonia | 6/29 (20.6) | 2/35 (5.6) | 0.1 | 4/21 (19) | 2/30 (6.6) | .02 | 4/20 (20) | 0 | 0.039 |
| Hospital admission | 6/29 (20.6) | 1/35 (2.8) | 0.04 | 5/21 (24) | 1/30 (3) | 0.07 | 5/20 (25) | 0 | 0.016 |
| Oxygen requirement | 4/29 (13.7) | 0 | 0.03 | 3/21 (14.2) | 0 | 0.06 | 3/20 (15) | 0 | 0.09 |
| ICU admission | 0 | 0 | ns | 0 | 0 | ns | 0 | 0 | ns |
| Allo-HSCT, n evaluable | 106 | 206 | 90 | 206 | 69 | 175 | |||
| SARS-CoV-2 infection, n (%) | 23 (21.7) | 19 (9.2) | 0.005 | 17 (18.8) | 16 (7.7) | 0.008 | 16 (23) | 13 (7.4) | 0.002 |
| Symptomatic SARS-CoV-2 | 15/23 (65) | 8/19 (42%) | 0.2 | 11/17 (65) | 6/16 (37.5) | 0.16 | 11/16 (69) | 5/13 (38) | 0.14 |
| Pneumonia | 4/23 (17.4) | 0/19 | 0.1 | 2/17 (11.7) | 0 | 0.4 | 2/16 (12.5) | 0 | 0.4 |
| Hospital admission | 4/23 (17.4) | 0 | 0.1 | 3/17 (17.6) | 0 | 0.2 | 3/16 (18.5) | 0 | 0.2 |
| Oxygen requirement | 3/23 (13) | 0 | 0.2 | 2/17 (11.7) | 0 | 0.4 | 2/16 (12.5) | 0 | 0.4 |
Allo-HSCT refers to allogeneic hematopoietic stem cell transplant, ASCT autologous stem cell transplantation, GvHD graft versus host disease, IS immunosuppressor drugs, NC not calculable when the subgroup had less than 5 patients.