TBE infection in an incomplete immunized person at-risk who lives in a high-endemic area—Impact on current recommendations for immunization of high-risk groups

Tick‐borne encephalitis in patients vaccinated against this disease

“…Of the 39 patients in the present study who developed breakthrough TBE, 22 (56.4%) were male, a sex ratio similar to that for all notified TBE cases in Slovenia (of 3304 patients ≥15 years old registered with TBE in Slovenia in 2000–2015, the proportion of males was 57.2%). However, vaccinated patients were older than 3304 patients registered with TBE in the same time period: median 59 (20–83) versus 44 (15–75+) years, respectively , which corresponds well with other reports indicating higher age in previously vaccinated patients with breakthrough TBE and implies less effective protection in older people, possibly due to decreased immunological responsiveness to vaccination and increased risk of vaccine failure . The exact mechanisms remain unknown.…”

“…Information on patients developing breakthrough TBE is limited, probably because numbers of such patients are low. A PubMed literature review identified 13 reports on patients with TBE despite vaccination , encompassing a total of 126 patients (Table ). Information on the severity of the acute illness is provided for only some of the patients.…”

“…Information on the severity of the acute illness is provided for only some of the patients. The relatively severe illness in several previously vaccinated patients was interpreted as the consequence of such patients being older than the average adult patient with TBE, higher age being a risk factor for a more severe course of the disease .…”

“…Our hypothesis was that the clinical course in patients with breakthrough TBE was more severe than in sex‐ and age‐matched unvaccinated patients. The premise was based on reports of relatively severe illness in several previously vaccinated patients . We assessed disease severity using simple clinical classification and quantitative evaluation (primary outcomes), and by the presence of individual clinical findings indicative of severe disease (secondary outcomes).…”

“…The number of patients reported as developing vaccination breakthrough TBE is low , and information on this group is limited. The aim of this study was to determine the proportion of such patients and to compare the course and outcome in this group with findings in unvaccinated patients who developed TBE.…”