Zens Kyra D, Haile Sarah R, Schmidt Axel J, Altpeter Ekkehardt S, Fehr Jan S, Lang Phung
Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.
Institute for Experimental Immunology, University of Zurich, Zurich, Switzerland.
BMJ Open. 2022 Apr 22;12(4):e061228. doi: 10.1136/bmjopen-2022-061228.
To estimate effectiveness of tickborne encephalitis (TBE) vaccination by time interval (<5, 5-10 and 10+years) postvaccination.
A retrospective, matched case-control study PARTICIPANTS: Cases-all adult (age 18-79) TBE cases in Switzerland reported via the national mandatory disease reporting surveillance system from 2006 to 2020 (final n=1868). Controls-community controls from a database of randomly selected adults (age 18-79) participating in a 2018 cross-sectional study of TBE vaccination in Switzerland (final n=4625).
For cases and controls, the number of TBE vaccine doses received and the time since last vaccination were determined. Individuals were classified as being 'unvaccinated' (0 doses), 'incomplete' (1-2 doses) or 'complete' (3+ doses). Individuals with 'complete' vaccination were further classified by time since the last dose was received (<5 years, 5-10 years or 10+ years). A conditional logistic regression model was used to calculate vaccine effectiveness (VE: 100 × [1-OR]) for each vaccination status category.
VE for incomplete vaccination was 76.8% (95% CI 69.0% to 82.6%). For complete vaccination, overall VE was 95.0% (95% CI 93.5% to 96.1%). When the most recent dose was received <5 years prior VE was 91.6% (95% CI 88.4% to 94.0%), 95.2% (95% CI 92.4% to 97.0%) when the most recent dose was received 5-10 years prior, and 98.5% (95% CI 96.8% to 99.2%) when the most recent dose was received 10+ years prior.
That VE does not decrease among completely vaccinated individuals over 10+ years since last vaccination supports the longevity of the protective response following complete TBE vaccination. Our findings support the effectiveness of 10-year TBE booster intervals currently used in Switzerland.
评估接种疫苗后不同时间间隔（<5年、5 - 10年和10年以上）的蜱传脑炎（TBE）疫苗接种效果。
一项回顾性匹配病例对照研究
病例——2006年至2020年通过国家法定疾病报告监测系统报告的瑞士所有成年（18 - 79岁）TBE病例（最终n = 1868）。对照——来自2018年瑞士TBE疫苗接种横断面研究中随机选择的成年人（18 - 79岁）数据库的社区对照（最终n = 4625）。
对于病例和对照，确定接受的TBE疫苗剂量数以及自上次接种以来的时间。个体被分类为“未接种”（0剂）、“未完成”（1 - 2剂）或“完成”（3剂及以上）。“完成”接种的个体进一步按自上次接种剂量以来的时间分类（<5年、5 - 10年或10年以上）。使用条件逻辑回归模型计算每个接种状态类别的疫苗有效性（VE：100×[1 - OR]）。
未完成接种的VE为76.8%（95%CI 69.0%至82.6%）。对于完成接种，总体VE为95.0%（95%CI 93.5%至96.1%）。当最近一剂在接种后<5年时，VE为91.6%（95%CI 88.4%至94.0%）；当最近一剂在接种后5 - 10年时，VE为95.2%（95%CI 92.4%至97.0%）；当最近一剂在接种后10年以上时，VE为98.5%（95%CI 96.8%至99.2%）。
自上次接种超过10年以上的完全接种个体中VE并未降低，这支持了TBE完全接种后保护性反应的持久性。我们的研究结果支持瑞士目前使用的10年TBE加强免疫间隔的有效性。
