Table 1.
Effectiveness of varicella vaccines.
| Outbreak investigations
| ||||||||
|---|---|---|---|---|---|---|---|---|
| Country [Reference] | Setting | Vaccine | N vaccinated cases | Vaccinated population | Vaccine doses | VE (%) (CI)
|
Vaccine coverage (%) | |
| Any disease | Moderate/severe disease | |||||||
| Germany [23] | Prospective, 7 day-care centers | Varilrix | 19 | 77 | 1 | 56 (29–72) | 86 (62–95) | 62 (49–81) |
| Priorix-Tetra | 7 | 38 | 1 | 55 (8–78) | 70 (4–90) | |||
| 2 | 56 | 2 | 91 (65–98) | 94 (54–99) | ||||
| Varivax | 4 | 48 | 1 | 86 (56–96) | 96 (67–99) | |||
| Italy [117] | Day-care center/elementary school | NR | 17 | 210 (Day care) | 1 | 60 (48–70) | – | 86.6 |
| 358 (School) | 1 | 69 (51–88) | – | 51.9 | ||||
| Italy [24] | Preschool | NR | 7 | 55 | 1 | 82.4 | – | 53.9 |
| USA [45] | Prospective elementary and affected schools | NR | 16 | 109 | 1 | 81 (67–89) | – | 32.7 |
| 9 | 220 | 2 | 95 (89–97) | – | 66.1 | |||
| 13 | 85 | 1 | 80 (64–89) | – | 31.4 | |||
| 22 | 181 | 2 | 84 (74–90) | – | 66.8 | |||
| Taiwan [118] | Elementary school | NR | 10 | 321 | NR | 69–100 | 86 | 71.2 |
| Israel [48] | Day-care centers | NR | 37 | 89 | NR | 20 (0–40) | 93 (75–98) | 37 |
| Case-control studies
| ||||||||
|---|---|---|---|---|---|---|---|---|
| Country [Reference] | Setting | Vaccine | N cases | N matched controls | Vaccine doses | VE (%) (CI)
|
Vaccine coverage (%) | |
| Any disease | Moderate/Severe disease | |||||||
| Germany [47] | Pediatric practices | Any | 432 | 432 | 1 | 86 (77–92) | 98 (91–99) | 13.2 (Cases); 45.1 (controls) |
| OKA/GSK | 35 | 63 | 1 | 72 (49–84) | 95 (78–99) | |||
| China [53] | General community | Any | 1000 | 1000 | 1 | 84 (77–89) | – | 19 |
| Varilrix | 1 | 86 (73–93) | – | |||||
| China [54] | Schools and day-care centers | Any | 180 | 679 | 1 | 83 (71–90) | – | 10.0 (Cases); 34.5 (controls) |
| USA: New Haven, Connecticut [119] | Pediatric practices | Any | 202 | 389 | 1 | 85 (78–90) | 97 (93–99) | 23 (Cases); 61 (controls) |
| USA: New Haven, Connecticut [44] | Pediatric practices | Any | 339 | 669 | 1 | 87 (81–91) | – | 36 (Cases); 70 (controls) |
| Note that this study expands upon results from the same source as Ref. [119] above | ||||||||
| USA: New Haven, Connecticut [46] | Pediatric practices | Any | 66 | 117 | 1 | 86 (−45–99) | – | 93.0 (Cases); 83.6 (controls) |
| Note that this study expands upon results from Refs. [119] and [44] above | 0 | 22 | 2 | 98 (84–100) | – | 0 (Cases) 15.7 (controls) | ||
| USA: Antelope Valley CA, Philadelphia [120] | Immunization registries | Any | 32 (1–3 years) | 103 (1–3 years) | 1 | 76 (39–90) | 78 (13–95) | |
| 93 (≥4 years) | 305 (≥4 years) | 2 | 94 (76–98) | 98 (83–100) | – | |||
| Korea [49] | National Notifiable Disease Surveillance | 1 MAV 3 OKA |
537 | 537 | 1 | 13 (−17–36) | – | – |
| Longitudinal, database, observational, and modeling studies
| ||||||||
|---|---|---|---|---|---|---|---|---|
| Country [Reference] | Setting | Vaccine | N cases | Sample size | Vaccine doses | VE (%) (CI)
|
Vaccine coverage (%) | |
| Any disease | Moderate/Severe disease | |||||||
| Turkey [21] | Well-child clinic and private pediatrician | Various | 466 | 1683 | 1 | 62 (57–66) | – | 60.1 |
| No vaccine | 723 | 1119 | 0 | – | ||||
| Germany [121] | Primary care modeling | Various | 679 | NR | 1 | 83 (80–86) | – | 78 |
| Germany [52] | Linear modeling based on Sentinel data | Various | 8153 | 31,288 | 1 | 87 (85–88) | – | 28.8 |
| 2 | 97 (97–98) | 58.8 | ||||||
CI: confidence intervals; N: number; NR: not reported; VE: vaccine effectiveness.