Tick-borne encephalitis in the Åland Islands, Finland: incidence and disease course since the implementation of a general TBE vaccination programme
Emerging Microbes & Infections·
- DOI
- 10.1080/22221751.2026.2640705
- PMID
- 41778286
- PMCID
- PMC13063329
- OpenAlex
- W7133496682
- Study type
- Journal article
- Publisher
- Informa UK Limited
- Article type
- journal-article
- Integrity
- current
Why this research matters now
The findings suggest that the Åland vaccination programme may have prevented an increase in TBE incidence seen in neighboring regions. The substantial proportion of breakthrough infections, particularly among incompletely vaccinated persons, highlights the importance of complete vaccination schedules for effective protection against severe TBE.
Structured evidence summary
Research question
The study examines the incidence, clinical presentation, and long-term outcomes of tick-borne encephalitis in the Åland Islands following the introduction of a regional vaccination programme in 2006.
Study design
This is a retrospective observational study of all patients diagnosed with TBE in Åland between 2006 and 2023 according to ECDC diagnostic criteria. Medical records were reviewed to collect epidemiological, laboratory, and clinical outcome data.
Population and setting
The study included 145 patients diagnosed with TBE in Åland, Finland, a TBE-endemic region. The cohort was 66% male with a median age of 53 years, and 10% were children under 18 years.
Main findings
The median TBE incidence was 29 per 100,000 per year, with no increase observed during the study period. Half of patients were unvaccinated, 32% incompletely vaccinated, and 14% completely vaccinated. Eighty-one percent required hospitalization, 9% needed intensive care, and two deaths occurred. Disease severity increased with age, and breakthrough infections were notably frequent among incompletely vaccinated individuals who more often developed severe disease. At two-year follow-up, 86% of patients had clinically recovered.
Public-health relevance
The findings suggest that the Åland vaccination programme may have prevented an increase in TBE incidence seen in neighboring regions. The substantial proportion of breakthrough infections, particularly among incompletely vaccinated persons, highlights the importance of complete vaccination schedules for effective protection against severe TBE.
Important limitations
This summary relies on the supplied single-article abstract and metadata. Full interpretation of study limitations, including potential surveillance biases, completeness of case ascertainment, and generalizability beyond Åland, requires review of the complete published article.
GIDS interpretation
The article was identified through classifier links for tick-borne encephalitis, Åland Islands/Finland, and vaccination. It provides regional epidemiological context from an endemic area with an established vaccination programme, useful for understanding TBE burden and vaccine effectiveness in similar settings.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 7 auditable classifier relationships to diseases, places, topics, and study design.