Open Study of the Duration of Immunity After Vaccination With GamEvac-Combi

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the post-vaccination immune status at different time points in subjects immunized against Ebola Virus Disease; to select an optimal regimen of product administration; and, to assess safety of medicinal product GamEvac-Combi - Combined Vector-Based Vaccine against Ebola Virus Disease, 0.5 ml+0.5 ml/dose, following the immunization with a half (0.25 ml+0.25 ml/dose) and full (0.5 ml+0.5 ml/dose) therapeutic doses.

Detailed Description
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This clinical trial is designed as an open study to evaluate the duration of immunity persistence following the administration of medicinal product GamEvac-Combi - Combined Vector-Based Vaccine against Ebola Virus Disease. It is an observational study; no interventions are planned in the course of common clinical practices during the study period; investigated therapeutic agents or special methods of examination will not be used in the study, except the blood sampling procedure specified in this Protocol. Only those patients who have signed the information consent form for participation in the study and have been informed by physician on the objectives and methods of this project will be involved in the study. The study consists of a single stage which is designed as a follow-up period to observe volunteers vaccinated in the course of evaluation of safety, reactogenic properties and immunogenicity of product GamEvac-Combi - Combined Vector-Based Vaccine against Ebola Virus Disease in the dosages of 0.25 ml and 0.5 ml, during the study under Protocol 01-COMBI-2015 in October-November 2015. Vaccination will not be made within the present study. Screening of volunteers is not required: the study will involve as many of the volunteers as possible (but not more than 60 subjects) who had been immunized earlier with GamEvac-Combi - Combined Vector-Based Vaccine against Ebola Virus Disease, provided that they have no medical contraindications for blood sampling. Study Schedule Visit 1 (outpatient): the goal of this visit is to assess whether a patient meets the inclusion/exclusion criteria. All procedures should be carried out upon receipt of the informed consent form signed by patient. The visit will be held 12 months after the vaccination. Visit 2 (outpatient): 18 months after the vaccination. Visit 3 (outpatient): 24 months after the vaccination. The duration of immunity persistence following product administration will be assessed in healthy volunteers based on the measurements of specific antibody titers. by ELISA method 12, 18 and 24 months after the vaccination vs. baseline values; in virus neutralization reaction 12 months after the vaccination vs. baseline values.

Official Title
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Open Study of the Duration of Immunity After Vaccination With Medicinal Product GamEvac-Combi - Combined Vector-Based Vaccine Against Ebola Virus Disease, 0.5 ml+0.5 ml/Dose

Conditions
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Ebola Hemorrhagic Fever

Intervention / Treatment
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* Procedure: blood sampling collection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males and females aged 18-56 who had been earlier vaccinated with medicinal product GamEvac-Combi in the dosages of 0.25 ml and 0.5 ml, during the study under Protocol 01-COMBI-2015 in October-November 2015. Written informed consent signed by patients prior to their involvement in the study Exclusion Criteria: Absence of the earlier vaccination with medicinal product GamEvac-Combi in the dosages of 0.25 ml and 0.5 ml, during the study under Protocol 01-COMBI-2015 in October-November 2015. Presence of a concomitant illness which could preclude obtaining a venous blood sample or affect the study process: (critical patient's condition, seizures, agitated state, blood loss and shocks of different origin).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 56 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| the dosage of 0.25 ml<br>Blood sampling collection: 12, 18 and 24 months after the vaccination. The study will enroll up to 30 healthy volunteers of both genders aged 18-55 inclusive who had been earlier immunized with medicinal product GamEvac-Combi in the dosages of 0.25 ml, during the study under Protocol 01-COMBI-2015 in October-November 2015. | Procedure: blood sampling collection<br>* It is an observational study; no interventions are planned in the course of common clinical practices during the study period; investigated therapeutic agents or special methods of examination will not be used in the study, except the blood sampling procedure and clinical observation specified in this Protocol.<br>|
| the dosage of 0.5 ml<br>Blood sampling collection: 12, 18 and 24 months after the vaccination. The study will enroll up to 30 healthy volunteers of both genders aged 18-55 inclusive who had been earlier immunized with medicinal product GamEvac-Combi in the dosages of 0.5 ml, during the study under Protocol 01-COMBI-2015 in October-November 2015 | Procedure: blood sampling collection<br>* It is an observational study; no interventions are planned in the course of common clinical practices during the study period; investigated therapeutic agents or special methods of examination will not be used in the study, except the blood sampling procedure and clinical observation specified in this Protocol.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| duration of immunity using ELISA method | To evaluate the duration of immunity persistence following the product administration in healthy volunteers by measuring the specific antibody titer: - using ELISA method 12 months after the vaccination vs. baseline values | 12 months after the vaccination | 
| duration of immunity using ELISA method | To evaluate the duration of immunity persistence following the product administration in healthy volunteers by measuring the specific antibody titer | 18 months after the vaccination | 
| duration of immunity using ELISA method | To evaluate the duration of immunity persistence following the product administration in healthy volunteers by measuring the specific antibody titer: - using ELISA method 24 months after the vaccination vs. baseline values | 24 months after the vaccination | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| duration of immunity in virus neutralization reaction | To evaluate the duration of immunity persistence following the product administration in healthy volunteers by measuring the specific antibody titer | 12 months after the vaccination vs. baseline values | 
| Incidence of Treatment-Emergent Adverse Events | Incidence of Treatment-Emergent Adverse Events. To assess product safety by collecting information on adverse events, development of infectious and non-infectious diseases, and on cases where vaccinated volunteers were seeking for medical care during the follow-up period | 12, 18 and 24 months after the vaccination | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ebola, Ebola Virus Vaccines, Haemorrhagic Fever, Ebola Infection, GP protein, Ebola virus