| 1. |
- Hansson, Karin, et al.
(författare)
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Tick-borne encephalitis (TBE) vaccine failures : A ten-year retrospective study supporting the rationale for adding an extra priming dose in individuals from the age of 50 years
- 2020
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press. - 1058-4838 .- 1537-6591. ; 70:2, s. 245-251
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Southern Sweden is endemic for tick borne encephalitis (TBE), with Stockholm County as one of the high-risk areas. The aim of this study was to describe cases of vaccine failures, and to optimize future vaccination recommendations.METHODS: Patients with TBE were identified in the notification database at the Department of Communicable Disease Control and Prevention in the county of Stockholm during 2006-2015. Vaccine failure was defined as TBE despite adherence to the recommended vaccination schedule with at least two doses. Clinical data were extracted from medical records.RESULTS: A total of 1004 TBE cases were identified, 53 (5%) were defined as vaccine failures. In this latter group the median age was 62 years (6-83). Forty-three (81%) patients were over 50 years of age and two were children. Approximately half of the patients had comorbidities with diseases affecting the immune system accounting for 26% of all cases.Vaccine failures following the third or fourth vaccine dose accounted for 36 (68%) of the patients. Severe and moderate TBE disease affected 81% of the cases.CONCLUSION: To our knowledge, this is the largest documented cohort of TBE-vaccine failures. Vaccine failure after five TBE-vaccine doses is rare. Our data provides rationale for adding an extra priming dose to the age group 50 years and older.
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| 2. |
- Varnaite, Renata, et al.
(författare)
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Magnitude and Functional Profile of the Human CD4(+) T Cell Response throughout Primary Immunization with Tick-Borne Encephalitis Virus Vaccine
- 2020
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Ingår i: Journal of Immunology. - : AMER ASSOC IMMUNOLOGISTS. - 0022-1767 .- 1550-6606. ; 204:4, s. 914-922
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Tidskriftsartikel (refereegranskat)abstract
- Tick-borne encephalitis (TBE) is a viral infection of the CNS caused by TBE virus. With no specific treatment available, the only protection is a formalin-inactivated whole virus vaccine. Primary immunization with European TBE vaccines, as recommended by the manufacturers, consists of three vaccine doses administered within a 1-y period. Protection from vaccination is believed to be mediated by Abs, yet T cells may also have a protective role. We set out to characterize the human CD4(+) T cell response throughout primary TBE immunization. The responses were evaluated before vaccination and 1 mo after each vaccine dose. A heterogeneous magnitude of CD4(+) T cell-mediated memory responses was observed in regard to lymphoblast expansion and cytokine production (IFN-gamma, IL-2, and TNF), with the highest median magnitude detected after the second dose of vaccine. Stimulation with an overlapping peptide library based on structural TBE virus proteins E and C revealed that CD4(+) T cells concomitantly producing IL-2 and TNF dominated the responses from vaccinees after each vaccine dose, whereas a control cohort of TBE patients responded mainly with all three cytokines. CD107a expression was not upregulated upon peptide stimulation in the vaccinees. However, CD154 (CD40L) expression on cytokine-positive memory CD4(+) T cells significantly increased after the second vaccine dose. Taken together, TBE vaccination induced CD4(+) T cell responses dominated by IL-2 and TNF production together with CD154 upregulation and a lower IFN-gamma response compared with TBE patients. This response pattern was consistent after all three doses of TBE vaccine.
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