E.1 Medical condition or disease under investigation |
E.1.1 | Medical condition(s) being investigated |
long-term B-cell immunity against tick-borne encephalitis (TBE) in healthy volunteers who have received 3-dose primary vaccination at an age between 18 and 31 years or older than 60 years. |
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E.1.1.1 | Medical condition in easily understood language |
protection after vaccination against tick-borne encephalitis |
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E.1.1.2 | Therapeutic area | Body processes [G] - Immune system processes [G12] |
MedDRA Classification |
E.1.3 | Condition being studied is a rare disease | No |
E.2 Objective of the trial |
E.2.1 | Main objective of the trial |
To determine the effect of age on long-term immunity after primary vaccination, a prospective study in volunteer participants who have received primary vaccination against tick-borne encephalitis (TBE), will be performed. The study includes 2 age groups: 1) healthy young adults who have received primary vaccination against TBE at 18-31 years of age, and 2) healthy old adults who have received primary vaccination against TBE at an age older than 60 years. Long-term B-cell-immunity will be assessed by determining TBEV-specifc antibody and memory B cells 3 years after primary vaccination. All study participants will receive the first booster vaccination with the licensed inactivated TBE vaccine (FSME-IMMUN, Baxter). Efficacy of booster vaccination will be compared among the 2 age groups by quantitative measurements of serum TBEV-specific antibody and memory B cell responses 1 and 4 weeks and 9 months after booster vaccination. |
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E.2.2 | Secondary objectives of the trial |
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E.2.3 | Trial contains a sub-study | No |
E.3 | Principal inclusion criteria |
Volunteers that have received 3-dose primary TBE vaccination in the primary study 3 years ago. TBE-vaccination criteria fulfilled. Participants of the primary study who have received 3-dose primary TBE vaccination but did not participate in the follow-up analysis will also be included. All participants have to understand and sign informed consent form (based on the judgement of the study physician) |
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E.4 | Principal exclusion criteria |
Contraindication to TBE vaccination (according to SmPC 2007) Immunodeficiency, history of autoimmune disease or current intake of immunomodulating drugs (corticosteroids) Pregnancy |
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E.5 End points |
E.5.1 | Primary end point(s) |
Frequency of TBEV-specific memory B cells measured by limiting dilution analysis |
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E.5.1.1 | Timepoint(s) of evaluation of this end point |
3 years after primary TBE vaccination and 1 and 4 weeks and 9 months after first booster vacination |
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E.5.2 | Secondary end point(s) |
Serum TBEV-specific IgG concentration and neutralizing antibody titer |
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E.5.2.1 | Timepoint(s) of evaluation of this end point |
3 years after primary TBE vaccination and 1 and 4 weeks and 9 months after first booster vacination |
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E.6 and E.7 Scope of the trial |
E.6 | Scope of the trial |
E.6.1 | Diagnosis | No |
E.6.2 | Prophylaxis | Yes |
E.6.3 | Therapy | No |
E.6.4 | Safety | No |
E.6.5 | Efficacy | Yes |
E.6.6 | Pharmacokinetic | No |
E.6.7 | Pharmacodynamic | No |
E.6.8 | Bioequivalence | No |
E.6.9 | Dose response | No |
E.6.10 | Pharmacogenetic | No |
E.6.11 | Pharmacogenomic | No |
E.6.12 | Pharmacoeconomic | No |
E.6.13 | Others | No |
E.7 | Trial type and phase |
E.7.1 | Human pharmacology (Phase I) | No |
E.7.1.1 | First administration to humans | No |
E.7.1.2 | Bioequivalence study | No |
E.7.1.3 | Other | No |
E.7.1.3.1 | Other trial type description | |
E.7.2 | Therapeutic exploratory (Phase II) | No |
E.7.3 | Therapeutic confirmatory (Phase III) | No |
E.7.4 | Therapeutic use (Phase IV) | Yes |
E.8 Design of the trial |
E.8.1 | Controlled | No |
E.8.1.1 | Randomised | No |
E.8.1.2 | Open | Yes |
E.8.1.3 | Single blind | No |
E.8.1.4 | Double blind | No |
E.8.1.5 | Parallel group | No |
E.8.1.6 | Cross over | No |
E.8.1.7 | Other | No |
E.8.2 | Comparator of controlled trial |
E.8.2.1 | Other medicinal product(s) | No |
E.8.2.2 | Placebo | No |
E.8.2.3 | Other | No |
E.8.3 |
The trial involves single site in the Member State concerned
| Yes |
E.8.4 | The trial involves multiple sites in the Member State concerned | No |
E.8.5 | The trial involves multiple Member States | No |
E.8.6 Trial involving sites outside the EEA |
E.8.6.1 | Trial being conducted both within and outside the EEA | No |
E.8.6.2 | Trial being conducted completely outside of the EEA | No |
E.8.7 | Trial has a data monitoring committee | No |
E.8.8 |
Definition of the end of the trial and justification where it is not the last
visit of the last subject undergoing the trial
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E.8.9 Initial estimate of the duration of the trial |
E.8.9.1 | In the Member State concerned years | 2 |
E.8.9.1 | In the Member State concerned months | |
E.8.9.1 | In the Member State concerned days | |