METHODS: Study staff at Rīga Stradinš University conducted nationwide active surveillance for TBEV infections. Serum and cerebrospinal fluid were ELISA-tested for TBEV-specific IgG and IgM antibodies. Vaccination history was collected by interview and medical record review. Utilizing data from surveillance and population surveys, vaccine effectiveness (with 95% CIs) and cases averted were estimated using the screening method.
RESULTS: There were 587 laboratory-identified TBE cases from 2018 to 2020; 98.1% (576/587) were unvaccinated, 1.5% (9/587) were unknown or partially vaccinated, and 0.3% (2/587) were fully vaccinated (three-dose primary series and appropriately timed boosters). TBE resulted in the death of 1.7% (10/587) of TBE cases. TBE vaccine history was ascertained from 92.0% (13 247/14 399) people from the general population: 38.6% (5113/13 247) were unvaccinated, 26.3% (3484/13 247) were fully vaccinated, and 35.1% (4650/13 247) were partially vaccinated. TBE vaccine effectiveness was 99.5% (98.0-99.9) against TBE, 99.5% (97.9-99.9) against TBE hospitalization, 99.3% (94.8-99.9) against moderate/severe TBE, and 99.2% (94.4-99.9) against TBE hospitalization >12 days. From 2018 to 2020, vaccination averted 906 TBE cases, including 20 deaths.
CONCLUSIONS: TBE vaccine was highly effective in preventing TBE, moderate and severe disease, and prolonged hospitalization. To prevent life-threatening TBE, TBE vaccine uptake and compliance should be increased in Latvia and other European regions where TBE is endemic.
方法:里加·斯特拉丁什大学的研究人员在全国范围内对TBEV感染进行了主动监测。血清和脑脊液进行TBEV特异性IgG和IgM抗体的ELISA检测。通过访谈和病历审查收集疫苗接种史。利用监测和人口调查的数据,使用筛选方法估计疫苗有效性(95%置信区间)和避免的病例.
结果:2018-2020年有587例实验室鉴定的TBE病例;98.1%(576/587)未接种疫苗,1.5%(9/587)未知或部分接种疫苗,和0.3%(2/587)完全接种疫苗(三剂主要系列和适当定时的加强剂)。TBE导致1.7%(10/587)的TBE死亡。从普通人群中92.0%(13,247/14,399)的人群中确定了TBE疫苗史:38.6%(5113/13,247)未接种疫苗,26.3%(3484/13,247)完全接种疫苗,35.1%(4650/13,247)接受了部分疫苗接种。TBE疫苗对TBE的有效性为99.5%(98.0-99.9),99.5%(97.9-99.9)反对TBE住院,99.3%(94.8-99.9)对中度/重度TBE,99.2%(94.4-99.9)的TBE住院时间>12天。从2018年到2020年,疫苗接种避免了906例TBE病例,包括20人死亡。
结论:TBE疫苗在预防TBE方面非常有效,中度和重度疾病,和长期住院。为了防止危及生命的TBE,在TBE流行的拉脱维亚和其他欧洲地区,应增加TBE疫苗的吸收和依从性。