Tick-Borne Encephalitis in Vaccinated Patients: A Retrospective Case-Control Study and Analysis of Vaccination Field Effectiveness in Austria From 2000 to 2018.
course of disease
tick-borne encephalitis
tick-borne encephalitis vaccination
vaccination failures
vaccine field effectiveness
Journal
The Journal of infectious diseases
ISSN: 1537-6613
Titre abrégé: J Infect Dis
Pays: United States
ID NLM: 0413675
Informations de publication
Date de publication:
14 02 2023
14 02 2023
Historique:
received:
18
11
2021
accepted:
01
03
2022
pubmed:
3
3
2022
medline:
17
2
2023
entrez:
2
3
2022
Statut:
ppublish
Résumé
There are discrepant observations on the severity of tick-borne encephalitis (TBE) in vaccinated persons. We, therefore, analyzed the occurrence of severe and mild disease in hospitalized vaccinated and nonvaccinated patients with TBE and determined the field effectiveness (FE) of vaccination against these forms of disease. The study covered all patients hospitalized with TBE in Austria from 2000 to 2018. Clinical diagnoses in vaccinated and age- and sex-matched nonvaccinated patients were compared in a nested case-control study. FE was calculated based on vaccination coverage and incidences in the nonvaccinated and vaccinated population. Of 1545 patients hospitalized with TBE, 206 were vaccinated. In those, a higher proportion of severe TBE was observed, especially in children. FE was high in all age groups and against all forms of disease. The higher proportion of severe TBE can be explained by a lower FE against severe than against mild disease, a difference especially pronounced in children (FE, 82.7% for severe vs 94.7% for mild disease). The FE of TBE vaccination is excellent. The observed higher proportion of severe disease in vaccinated persons with TBE does not reflect a higher risk associated with vaccination but is rather due to a somewhat lower FE against severe TBE. Because this effect was more pronounced in children, we recommend adapting the immunization schedule.
Sections du résumé
BACKGROUND
There are discrepant observations on the severity of tick-borne encephalitis (TBE) in vaccinated persons. We, therefore, analyzed the occurrence of severe and mild disease in hospitalized vaccinated and nonvaccinated patients with TBE and determined the field effectiveness (FE) of vaccination against these forms of disease.
METHODS
The study covered all patients hospitalized with TBE in Austria from 2000 to 2018. Clinical diagnoses in vaccinated and age- and sex-matched nonvaccinated patients were compared in a nested case-control study. FE was calculated based on vaccination coverage and incidences in the nonvaccinated and vaccinated population.
RESULTS
Of 1545 patients hospitalized with TBE, 206 were vaccinated. In those, a higher proportion of severe TBE was observed, especially in children. FE was high in all age groups and against all forms of disease. The higher proportion of severe TBE can be explained by a lower FE against severe than against mild disease, a difference especially pronounced in children (FE, 82.7% for severe vs 94.7% for mild disease).
CONCLUSIONS
The FE of TBE vaccination is excellent. The observed higher proportion of severe disease in vaccinated persons with TBE does not reflect a higher risk associated with vaccination but is rather due to a somewhat lower FE against severe TBE. Because this effect was more pronounced in children, we recommend adapting the immunization schedule.
Identifiants
pubmed: 35235953
pii: 6541329
doi: 10.1093/infdis/jiac075
doi:
Substances chimiques
Viral Vaccines
0
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
512-521Informations de copyright
© The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.
Déclaration de conflit d'intérêts
Potential conflicts of interest. The project was supported by Pfizer as an IIR project (grant WI235042; with H. H. and M. K. as principal investigators and I. S. involved in the project); and by the Center for Virology, Medical University of Vienna. The Center for Virology received an IIR grant from Pfizer (grant WI239484; “Epidemiological changes of TBE in Austria,” with K. S. as principal investigator). All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.