Table 1.
Characteristics and results of the anti-TBE vaccine efficacy studies
| Author/year | Type of study | Follow-up period | Vaccination | Population | Vaccination schedule | VE (%) (95%CI) | |||
|---|---|---|---|---|---|---|---|---|---|
| Population | Population size (n/N)* | ||||||||
| Erber 2022 [13] | Ecological study | 12 years 2007–2018 | FSME-Immun®/Encepur® | Residents of areas of endemic prevalence | Germany (Bavaria and Baden-Württemberg) | 75/3,366,349 (I) 3,010/9,747,843 (C) | Completion of the basic schedule (3 doses) | 92.8 (0.909–0.943) | |
| 50/3,530,490 (I) 3,010/9,747,843 (C) | Administration of the first booster dose after completing the basic schedule | 95 (0.939–0.965) | |||||||
| Latvia | 13/308.420 (I) 3,044/800,481 (C) | Completion of the basic schedule (3 doses) | 98.9 (0.981–0.994) | ||||||
| 18/407.183 (I) 3,044/800,481 (C) | Administration of the first booster dose after completing the basic schedule | 98.8 (0.982–0.993) | |||||||
| Nygren 2022 [20] | A case control study | –2020 | FSME-Immun®/Encepur® | Residents of the areas of endemic prevalence in Bavaria and Baden-Württemberg (Germany) | 13/235 | Completion of the full vaccination schedule (≥ 3 doses) administered on time as recommended by the manufacturer | 96.6 (0.937–0.982) | ||
| 8/105 | Completion of the full ENCEPUR vaccination schedule (≥ 3 doses) | 95.8 (0.897–0.983) | |||||||
| 13/106 | Completion of the full FSME-IMMUN vaccination schedule (≥ 3 doses) | 90.1 (0.866–0.965) | |||||||
| 16/145 | Completion of the basic schedule (3 doses) | 91.9** **(0.852–0.956) | |||||||
| 20/280 | Administration of the first booster dose after completing the basic schedule (4 doses) | 95.9** (0.926–0.977) | |||||||
| Zens 2022 [21] | A case control study | 5, 5–10, and 10 years | FSME-Immun®/Encepur® | Individuals aged 18 to 79, with or without TBE, residing in Switzerland in years 2006–2020 | 48/522 | Completed vaccination schedule (3 or more doses) | < 5 years | 91.6 (0.884–0.940) | |
| 20/397 | 5–10 years | 95.2 (0.924–0.970) | |||||||
| 8/458 | > 10 years | 98.5 (0.968–0.992) | |||||||
| 76/1377 | Total | 95 (0.935–0.961) | |||||||
(I) investigation group, (C) control group, VE – vaccine effectiveness
* N case, N number of people in the intervention or control group
** univariable estimates