Table 6 SARS-CoV-2 breakthrough infection severity according to the timing of vaccine doses and SARS-CoV-2 variant of concern period in the whole cohort and in allo-HSCT recipients.
Variable | After 2 doses | After 3 doses | After 4 doses | P value | Alpha-beta period | Delta period | Omicron period | P value |
|---|---|---|---|---|---|---|---|---|
Whole cohort | 31 | 40 | 8 | 9 | 15 | 55 | ||
Symptomatic SARS-CoV-2 | 14/31 (45) | 20/40 (50) | 6/8 (75) | 0.3 | 2/9 (22) | 2/15 (13) | 36/55 (65) | <0.001 |
Pneumonia | 7/31 (22.6) | 2/40 (5) | 0 | 0.03 | 1/9 (11) | 2/15 (13) | 6/55 (11) | 0.9 |
Hospital admission | 6/31 (19.3) | 2/40 (5) | 0 | 0.08 | 1/9 (11) | 1/15 (6.5) | 6/55 (11) | 0.8 |
Oxygen requirement | 4/31 (13) | 1/40 (2.5) | 0 | 0.1 | 1/9 (11) | 1/15 (6.5) | 3/55 (5.5) | 0.8 |
ICU admission | 1/31 (3.2) | 0 | 0 | ns | 1/9 (11) | 0 | 0 | 0.01 |
Allo-HSCT, n evaluables | 17 | 28 | 5 | 6 | 8 | 39 | ||
Symptomatic SARS-CoV-2 | 10/17 (59) | 14/28 (50) | 4/5 (80) | 0.4 | 2/6 (33) | 2/8 (25) | 25/39 (64) | 0.06 |
Pneumonia | 3/17 (17.6) | 1/28 (3.5) | 0 | 0.1 | 1/6 (16) | 2/8 (25) | 2/39 (5) | 0.1 |
Hospital admission | 2/17 (11.7) | 2/28 (7) | 0 | 0.6 | 1/6 (16) | 1/8 (12.5) | 3/39 (7) | 0.7 |
Oxygen requirement | 2/17 (11.7) | 1/28 (3.5) | 0 | 0.4 | 1/6 (16) | 1/8 (12.5) | 2/39 (5) | 0.5 |
ICU admission | 0 | 0 | 0 | ns | 1/6 (16) | 0 | 0 | 0.01 |
