Adequate vaccination is effective in preventing tick-borne encephalitis (TBE). A population survey conducted in 2015 in Czech Republic, Estonia, Finland, Germany, Hungary, Latvia, Lithuania, Poland, Slovakia, Slovenia, and Sweden obtained information on TBE vaccination. Respondents answered 10 questions for themselves and household members. Data were weighted according to age and fine-tuned for geographical spread. Across the 10 countries (excluding Poland), TBE awareness was 83%; of all respondents, 68% were aware of TBE vaccines and 25% had ≥1 injections. Vaccination rates were lowest in Finland and Slovakia (∼10%), highest in Austria (85%, results from a separate 2015 survey), and varied widely in Germany. Across the 11 countries (excluding Austria), compliance with vaccination schedule among TBE-vaccinated respondents was 61%; 27% and 15% of respondents received first and second booster injections; strongest motivators for vaccination were fear of TBE (38%) and residence/spending time in high-risk areas (31-35%); main reasons for not receiving vaccination were beliefs that vaccination was unnecessary (33%) and that there was no risk of contracting TBE (23%). TBE vaccine uptake and compliance could be improved with effective public health information to increase TBE awareness and trust in vaccination and by updating recommendations to include all subjects visiting TBE-risk areas.

There has been an increase in reported TBE cases in Europe since 2015, reaching a peak in some countries in 2020, highlighting the need for better management of TBE risk in Europe. TBE surveillance is currently limited, in part, due to varying diagnostic guidelines, access to testing, and awareness of TBE. Consequently, TBE prevalence is underestimated and vaccination recommendations inadequate. TBE vaccine uptake is unsatisfactory in many TBE-endemic European countries. This review summarizes the findings of a scientific workshop of experts to improve TBE surveillance and vaccine uptake in Europe. Strategies to improve TBE surveillance and vaccine uptake should focus on: aligning diagnostic criteria and testing across Europe; expanding current vaccine recommendations and reducing their complexity; and increasing public education of the potential risks posed by TBEV infection.

Tick-borne encephalitis (TBE) is a vaccine-preventable disease which may cause long-term sequelae and even death. The data on the long-term effectiveness of TBE vaccines are limited. Additionally, the vaccination schedule is complex which in part contributes towards sub-optimal uptake in TBE-endemic areas. The current ecological study measures vaccine effectiveness (VE) in two European countries. TBE VE was measured from 2007 to 2018 in Latvia and Southern German states by age group, vaccination history, and schedule compliance. TBE cases and vaccination history were obtained from the public health agencies for Latvia and the southern German federal states of Bavaria and Baden-Wuerttemberg. Cases were "within schedule" if a TBE infection was diagnosed within the time interval preceding the next scheduled dose and "outside schedule" if the diagnosis occurred after the next scheduled dose. Vaccine uptake was estimated via representative nationwide surveys. VE after 2, 3, and ≥4 doses was high in both countries at 97.2%, 95.0%, and 95.4% for southern Germany, and 98.1%, 99.4%, and 98.8% for Latvia while within- schedule, and only showed marginal differences outside schedule at 90.6%, 89.9%, and 95.6% for southern Germany, and 97.4%, 98.4%, and 99.0% for Latvia regardless of age groups. In both countries, VE after two and three primary doses within-schedule was very high in all age groups. Once receiving booster doses, high VE continued to be observed even in persons with extended intervals since the last dose received, suggesting that longer and more flexible booster intervals may be considered for sustainable long-term protection.

Tick-borne encephalitis (TBE) vaccines are highly effective in preventing TBE and vaccine failures (VF) are rare events. In this study, we compared the age distribution of TBE cases and TBE VF in three endemic countries: Sweden, Southern Germany, and Latvia. While the age distribution of TBE cases was similar for those <50 years versus those ≥50 years in all three countries, in Sweden, a higher proportion of VF cases was ≥50 years, whereas most VF cases in Latvia were <50 years of age and more evenly distributed between those <50 years versus those ≥50 in Southern Germany. Here, theoretical explanations were provided, including differences in diagnostic practices, vaccine uptake between age groups, behavioral patterns and underlying medical conditions, as to why VF were generally older in Sweden than the other countries. There is no scientific rationale to give an extra priming dose of TBE vaccine to subjects ≥50 years of age.

There is very little information and there are only a few publications on TBE in Kyrgyzstan. A survey by Atkinson1 references the following: In humans and birds low seropositivity has been demonstrated as early as 1973. In 1978 the TBEV was isolated from ticks, and twelve human cases were reported between 1976–1981.