MedPath

Primary TBE Vaccination for the Elderly

Phase 4
Not yet recruiting
Conditions
Vaccine
Tick-borne Encephalitis
Interventions
Drug: FSME-IMMUN Vaccine
Registration Number
NCT04573205
Lead Sponsor
Region Örebro County
Brief Summary

Tick-borne Encephalitis (TBE) can be prevented by vaccine. Vaccine failure, defined as a case of TBE regardless of previous vaccination, has been described and seems to be more predominant with increasing age, suggesting a less effective immune response following with increasing age. In fact previous studies has shown a reduced antibody response in elderly individuals compared to younger when vaccinated against TBE. As a result, in Sweden, an extra vaccine dose has been recommended during the primary vaccine schedule to individuals \> 50 years of age. This alternative vaccine schedule has not been tested. The investigator aim to test if an extra vaccine dose in the primary vaccine schedule for those \> 50 years of age improves the immune response and offers a corresponding immunity to younger individuals following TBE vaccination.

Detailed Description

Not available

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
90
Inclusion Criteria
  • Adults ≥ 50 years or between 18-40 years
  • Man or woman
  • God health
  • Written informed consent
Exclusion Criteria
  • Previous vaccination against TBE
  • Previous TBE infection
  • Allergy or hypersensitivity to any substance in the vaccine
  • Previously known or suspected infection with Japanese encephalitis, Dengue virus, West Nile fever or Yellow fever
  • Information on previous vaccination against Yellow fever or Japanese encephalitis
  • Acute illness, eg fever with malaise
  • Immunosuppression, due to medication or disease
  • Previous treatment with Rituximab or equivalent
  • Autoimmune disease, including diabetes (diet or tablet-treated diabetes with good metabolic control is accepted, HbA1c < 6 %)
  • Obesity, BMI > 40
  • Moderate to severe renal failure including hemodialysis, estimated GFR < 30.
  • Blood transfusion or immunoglobulins <3 months ago
  • Pregnancy
  • Any other illness where the investigator consider the subject unsuitable for the study
  • The study subject does not want to participate

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
> 50 yearsFSME-IMMUN VaccineHealthy individuals \> 50 years of age divided into age groups 50-59 years, 60-69 years and \>70 years, approximately 20 participants in each group. Vaccinated with 4 doses FSME immune Adult intramuscular injection according to the recommended primary vaccine Schedule in Sweden for individuals \> 50 years of age, at time 0, 1, 2 and 7 months.
< 40 yearsFSME-IMMUN VaccineHealthy individuals \< 40 years of age. Vaccinated with 3 doses FSME immune Adult intramuscular injection according to the standard recommended primary vaccine at time 0, 1, and 7 months.
Primary Outcome Measures
NameTimeMethod
Serological response to vaccination with TBE vaccine following primary vaccinationNT measured 1 months after vaccination

The proportion of individuals \> 50 years that achieves protective levels following the extra primary vaccine dose compared to the proportion of individuals tha achieve protective levels of neutralizing antibodies following the second vaccine dose in those \< 40 years.

Serological response to vaccination with TBE vaccine following the full vaccine scehduleNT measured 1 months after vaccination

The proportion of individuals \> 50 years that achieves protective levels of neutralizing antibodies following the final primary schedule ( dose 4), compared to those \< 40 years ( 3 doses).

Secondary Outcome Measures
NameTimeMethod
Cellular immunity in young and elderly ( immune cell expression)Measured 7 days after vaccination

T and B cell populations (flow cytometry) 7 days after TBE vaccination

Cellular immunity in young and elderly ( cytokine production)Measured 7 days after vaccination

Cytokine production ( Luminex) 7 days after TBE vaccination

Trial Locations

Locations (1)

Region Örebro Län

🇸🇪

Örebro, Sweden

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