Table 4.
Breakthrough infection and symptomatic COVID-19 of the SARS-CoV-2 Delta variant.
| Type of disease | Age (year) | Weeks post final vaccination | No. of studies | P h/I 2 (%) | Incidence per 100 person years (95% CI) | RR (95% CI) | P | Vaccine name |
|---|---|---|---|---|---|---|---|---|
| RCT studies: symptomatic COVID-19 | ≥18 | 26-34 | 2 | 0.512/0.0 | 5.0 (4.1, 6.0) | Ref | Ref | mRNA-1273 |
| 34-56 | 3 | 0.507/0.0 | 7.4 (6.6, 8.2) | 1.41 (1.15, 1.73) | <0.001 | |||
| 18-64 | 26-34 | 1 | NA | 5.3 (4.1, 6.5) | Ref | Ref | mRNA-1273 | |
| ≥65 | 3.9 (2.3, 5.6) | 0.76 (0.47, 1.23) | NA | |||||
| 18-64 | 34-56 | 1 | NA | 8.7 (7.3, 10.1) | Ref | Ref | mRNA-1273 | |
| ≥65 | 4.8 (3.0, 6.6) | 0.57 (0.38, 0.86) | <0.001 | |||||
| Cohort studies: symptomatic COVID-19 | ≥18 | 2-21 | 9 | <0.001/99.8 | 0.6 (0.5, 0.8) | Ref | Ref | mRNA-1273; BNT162b2; Ad26.COV2.S |
| 4-26 | 9 | <0.001/99.2 | 0.8 (0.6, 1.0) | 1.06 (1.03, 1.08) | <0.001 | |||
| 9-34 | 6 | <0.001/99.5 | 0.8 (0.6, 1.0) | NA | NA | mRNA-1273; BNT162b2 | ||
| 18-49 | 2-21 | 3 | <0.001/99.6 | 0.9 (0.6, 1.2) | Ref | Ref | mRNA-1273; BNT162b2; Ad26.COV2.S | |
| 50-64 | <0.001/99.2 | 0.6 (0.3, 0.8) | 0.57 (0.55, 0.59) | <0.001 | ||||
| ≥65 | <0.001/99.2 | 0.4 (0.3, 0.6) | 0.49 (0.47, 0.51) | <0.001 | ||||
| 18-49 | 4-26 | 3 | <0.001/99.2 | 1.2 (0.8, 1.6) | Ref | Ref | ||
| 50-64 | <0.001/97.8 | 0.7 (0.5, 1.0) | 0.66 (0.63, 0.70) | <0.001 | ||||
| ≥65 | <0.001/97.8 | 0.5 (0.3, 0.7) | 0.43 (0.41, 0.45) | <0.001 | ||||
| 18-49 | 9-34 | 2 | <0.001/99.5 | 1.1 (0.7, 1.6) | Ref | Ref | mRNA-1273; BNT162b2 | |
| 50-64 | <0.001/98.2 | 0.7 (0.5, 1.0) | 0.65 (0.62, 0.69) | <0.001 | ||||
| ≥65 | <0.001/99.0 | 0.6 (0.3, 0.8) | 0.55 (0.53, 0.58) | <0.001 | ||||
| Cohort studies: SARS-CoV-2 infection | ≥18 | 2-10 | 3 | <0.001/99.8 | 1.1 (0.2, 2.0) | Ref | Ref | mRNA-1273; BNT162b2; Ad26.COV2.S |
| 10-18 | <0.001/98.7 | 4.1 (0.2, 8.1) | 2.93 (2.84, 3.02) | <0.001 | ||||
| 18-26 | <0.001/98.9 | 6.1 (1.7, 10.5) | 3.03 (2.94, 3.13) | <0.001 | ||||
| 26-33 | <0.001/99.6 | 9.3 (3.4, 15.3) | 4.22 (4.07, 4.38) | <0.001 | ||||
| ≥ 33 | <0.001/99.7 | 12.3 (4.1, 20.5) | 5.79 (5.52, 6.07) | <0.001 | ||||
| ≥18 | 2-10 | 3 | 0.023/73.4 | 1.5 (1.4, 1.6) | Ref | Ref | mRNA-1273; BNT162b2 | |
| 10-18 | <0.001/99.7 | 5.4 (3.5, 7.3) | 2.98 (2.89, 3.07) | <0.001 | ||||
| 18-26 | <0.001/97.8 | 6.1 (4.7, 7.5) | 2.92 (2.82, 3.02) | <0.001 | ||||
| 26-33 | <0.001/99.2 | 8.1 (2.8, 13.3) | 3.69 (3.55, 3.84) | <0.001 | ||||
| ≥ 33 | 0.093/58.0 | 10.1 (7.7, 12.5) | 5.76 (5.49, 6.04) | <0.001 | ||||
| 18-49 | 2-26 | 3 | <0.001/97.8 | 6.0 (1.4, 10.5) | Ref | Ref | mRNA-1273; BNT162b2; Ad26.COV2.S | |
| 50-64 | <0.001/98.2 | 4.3 (1.2, 7.5) | 0.83 (0.81, 0.85) | <0.001 | ||||
| ≥65 | <0.001/99.3 | 1.0 (0.1, 2.0) | 0.31 (0.30, 0.32) | <0.001 | ||||
| 18-49 | ≥ 26 | 2 | <0.001/98.8 | 16.1 (10.0, 22.2) | Ref | Ref | ||
| 50-64 | 0.006/86.8 | 11.5 (9.9, 13.0) | 0.78 (0.73, 0.82) | <0.001 | ||||
| ≥65 | <0.001/97.3 | 4.8 (3.6, 6.0) | 0.33 (0.31, 0.35) | <0.001 |
Ref, reference; NA, not available.