Baroutsou et al.
Analysis of tick-borne encephalitis vaccination coverage and compliance in adults in Switzerland, 2018
Vaccine. 2020; 38: 7825-7833
Since the first description of a TBE case in Switzerland in 1969, the TBE virus has been spreading in this country with increasing numbers of yearly reported cases and an incidence high of 4.37 cases per 100,0000 individuals. However, the incidence is heterogenous in Switzerland and vaccination is generally recommended by the Federal Office of Public Health (FOPH) for the whole country except the two cantons of Geneva and Ticino.
A national survey has been carried out together with the FOPH in all 26 cantons in order to evaluate the TBE vaccination coverage in adults aged 18-79 years of age. Individuals were contacted by mail and were requested for their vaccination booklet and a short questionnaire with four questions about their perception and attitudes regarding TBE and TBE vaccination.
From 28,880 randomly selected individuals, a total of 4,479 individuals responded both with a complete questionnaire and the vaccination record, and these persons were termed „participants“. Among these participants, the national TBE vaccination coverage was 42% for one dose (from 14% in Ticino region and 60% in Zurich region) and 33% (from 8% in Ticino region and 50% in Zurich region) for a complete primary series of three doses. Booster coverage was highest in the cantons Thurgau and Glarus with 24% and 23% respectively.
Based on the estimate for national TBE incidence among non-vaccinated adults, a vaccine effectiveness of 90.2-92.0% has been calculated. The authors estimated that 112-162 TBE cases were prevented among adults in Switzerland alone for 2018.
Reasons for not being vaccinated were i) at low risk, ii) not enough information about TBE, or iii) about the vaccine, iv) skeptical about vaccination in general, v) not enough time, vi) vaccine too expensive.
These data show that with only a third of the adults having received a complete primary TBE vaccination, the vaccination coverage is too low in Switzerland, and public health interventions (risk perception and behaviors) have to be improved.