Effect of Selenium Supplementation on Influenza Vaccination

Study Overview
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Brief Summary
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The study is designed to assess whether selenium supplementation can boost the immunity response to influenza vaccination in healthy adults. This is a randomized, prospective study enrolling a total of 60 healthy subjects, 18-55 years old.

Detailed Description
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Background: Selenium is an essential trace element required for human health and wellbeing. Despite mouse studies and human clinical trial suggest selenium supplementation might enhance immunity, little is known for the effects of selenium supplementation on humoral immunity. Vaccination is the most effective medical intervention to prevent infections and to reduce disability and mortality associated with infectious disease. However, some individuals, in healthy or disease conditions, mount less effective humoral immune responses to vaccination. Therefore, new strategy to enhance humoral immunity upon vaccination is highly sought after. Using mouse models, we have observed that selenium supplementation significantly increased antigen-specific antibody responses. Thus, we hypothesize that selenium supplementation may be beneficial in enhancing humoral immunity in humans. Objectives: To investigate whether selenium supplementation will boost the humoral response to influenza vaccination in healthy adults. Design and trial size: This is a randomized prospective study. A total of 60 healthy subjects, 18-55 years old, will be enrolled in this study. Intervention and duration: The enrolled subjects will be randomized into selenium supplementation and control group. The selenium supplementation group will receive 200 μg selenium daily by taking two selenium-enriched yeast tablets (SelenoPrecise®, Pharma Nord) once daily for 60 days. The control group will not receive selenium supplementation. Thirty days after allocation, both groups will receive standard seasonal influenza vaccination for the 2019-2020 season. Peripheral blood samples will be collected at baseline (day 0, prior to treatment), day 30, day 37 (7 days after vaccination) and day 60 (30 days after vaccination).

Official Title
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Effect of Selenium Supplementation on Immunity Responses to Influenza Vaccination

Conditions
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Selenium Supplementation, Influenza Vaccination

Intervention / Treatment
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* Dietary Supplement: Selenium Supplementation
* Biological: Influenza vaccination


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-55 years, healthy subjects Exclusion Criteria: With the history of selenium supplementation as taking supplementation products or living more than 2 years in selenium-enriched area; Had the symptoms of selenium toxicity or serum selenium level greater than 328 μg/L; With the history of the administration of influenza vaccine in past three years or allergic to influenza vaccine; With any current immunologic disorders, including autoimmune and allergic diseases; With any cardiovascular, metabolic, mental, or psychological disorders; Pregnancy or breastfeeding; With the history of infectious diseases including airway infections in past three months; Who are currently participating in other clinical studies or who have participated in other clinical research within 90 days

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 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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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Selenium Supplementation<br>The selenium supplementation group will receive 200 μg selenium daily by taking two selenium-enriched yeast tablets (SelenoPrecise®, Pharma Nord) once daily for 60 days. Thirty days after the start of the supplementation, the subjects will receive standard seasonal influenza vaccination for the 2019-2020 season. | Dietary Supplement: Selenium Supplementation<br>* The selenium supplementation group will receive 200 μg selenium daily by taking two selenium-enriched yeast tablets (SelenoPrecise®, Pharma Nord) once daily for 60 days.<br>Biological: Influenza vaccination<br>* Subjects will receive standard seasonal influenza vaccination for the 2019-2020 season.<br>|
| Other: Non-Selenium Supplementation<br>The control group will not receive selenium supplementation. Thirty days after allocation, the subjects will receive standard seasonal influenza vaccination for the 2019-2020 season. | Biological: Influenza vaccination<br>* Subjects will receive standard seasonal influenza vaccination for the 2019-2020 season.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The production of antigen-specific antibodies after vaccination | Viral strain-specific antibodies in serum at baseline (day 0, prior to treatment), day 30, day 37 (7 days after vaccination) and day 60 (30 days after vaccination) will be measured by hemagglutination inhibition (HAI) assay | 60 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Immune cell responses after selenium supplementation and vaccination | Frequencies (%) of immune cells including T cells, B cells, monocytes, dendritic cells, NK cells in peripheral blood at baseline (day 0, prior to treatment), day 30, day 37 (7 days after vaccination) and day 60 (30 days after vaccination)will be measured by flow cytometry. | 60 days | 
| Immune cytokine IFN-γ after selenium supplementation and vaccination | Levels of IFN-γ in plasma at baseline (day 0, prior to treatment), day 30, day 37 (7 days after vaccination) and day 60 (30 days after vaccination) will be measured by enzyme-linked immunosorbent assay (ELISA). | 60 days | 
| Immune cytokine IL-4 after selenium supplementation and vaccination | Levels of IL-4 in plasma at baseline (day 0, prior to treatment), day 30, day 37 (7 days after vaccination) and day 60 (30 days after vaccination) will be measured by enzyme-linked immunosorbent assay (ELISA). | 60 days | 
| Immune cytokine IL-10 after selenium supplementation and vaccination | Levels of IL-10 in plasma at baseline (day 0, prior to treatment), day 30, day 37 (7 days after vaccination) and day 60 (30 days after vaccination) will be measured by enzyme-linked immunosorbent assay (ELISA). | 60 days | 
| Immune cytokine IL-17A after selenium supplementation and vaccination | Levels of IL-17A in plasma at baseline (day 0, prior to treatment), day 30, day 37 (7 days after vaccination) and day 60 (30 days after vaccination) will be measured by enzyme-linked immunosorbent assay (ELISA). | 60 days | 
| Immune cytokine IL-21 after selenium supplementation and vaccination | Levels of IL-21 in plasma at baseline (day 0, prior to treatment), day 30, day 37 (7 days after vaccination) and day 60 (30 days after vaccination) will be measured by enzyme-linked immunosorbent assay (ELISA). | 60 days | 
| Selenium levels after selenium supplementation and vaccination | Level of selenium in plasma at baseline (day 0, prior to treatment), day 30, day 37 (7 days after vaccination) and day 60 (30 days after vaccination) will be measured by inductively coupled plasma mass spectrometry (ICP-MS). | 60 days |