Ignite Creation Date:
2024-05-05 @ 11:55 AM
Last Modification Date:
2024-10-26 @ 9:16 AM
Study NCT ID:
NCT00170482
Status:
COMPLETED
Last Update Posted:
2019-01-28
First Post:
2005-09-09
Brief Title:
Elderly Influenza Vaccine Immunogenicity Substudy
Sponsor:
National Institute of Allergy and Infectious Diseases NIAID
Organization:
National Institute of Allergy and Infectious Diseases NIAID
Study Overview
Official Title:
In Depth Immunologic Studies in Elderly Subjects Receiving Either Standard-Dose Fluzone 15mcg HAVirus Strain or High-Dose 60 mcg HAVirus Strain Trivalent Inactivated Influenza Virus Vaccine
Status:
COMPLETED
Status Verified Date:
2011-04-26
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
No
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
The bodys immune system fights infection is known to decline during the aging process resulting in an increased risk of catching infections Vaccinations also are not as effective in protecting older people against infection as they are in younger people The purpose of this study is to better understand how and why vaccines are not as effective in older people The researchers believe that the immune response in older people who get a higher dose vaccine will be similar to the immune response in young adults who get the standard lower dose vaccine This study is a substudy to a main study evaluating flu vaccines in people 65 years and older Volunteers who are in the main study will be asked if they will participate in the substudy The substudy requires them to give 2 additional blood samples for an in-depth look at their immune response to the flu vaccine given in the main study Substudy volunteers will have up to 3 clinic visits and participate up to 28 weeks
Detailed Description:
There is a need to increase protection against influenza conveyed to elderly persons by inactivated influenza virus vaccines Serum antibody titer is the primary surrogate marker for immunity to influenza after vaccination and increasing the antigen dose has been shown to increase the serum antibody response in vaccinated persons including the elderly However it is not known how the remainder of the immune system responds to the higher dose of influenza antigen This study is linked to DMID protocols 04-100 and 05-0055 This study will be conducted as a substudy of DMID 04-100 at the University of Maryland Baltimore Subjects ages 65 years and older who meet the entry criteria for the primary study will be approached for participation in an immunology substudy of volunteers who receive a single intramuscular injection of either the high-dose or standard-dose of licensed 2004-2005 trivalent inactivated influenza vaccine A minimum of 30 elderly subjects with the possibility of up to 60 elderly subjects will be enrolled for the substudy The substudy will require an extra 100 ml total blood draw of 120 ml of blood drawn from the same 20 ml venipuncture obtained for hemagglutination inhibition assay HAI titers as per the primary study on days 0 and 28 To minimize adverse side effects the additional 100 ml of blood required for the substudy will be obtained from the same venipuncture site from which the 20 ml blood will be obtained for HAI titers ie if blood collection stops after the 20 ml for HAI are drawn the researchers will not attempt to obtain additional blood from a separate venipuncture site Subjects blood will be evaluated for key humoral and cell-mediated immunity CMI responses to better understand the mechanisms underlying the predicted suboptimal immune responses to one or more of the three influenza vaccine antigens observed in the elderly With regard to specific study objectives blood samples will be submitted for the following analysis 1 measurement of serum anti-HA hemagglutinin IgG and IgA antibodies by ELISA 2 IgG antibody subclasses 3 IgG and IgA avidity 4 virus neutralizing functional assay and 5 HAI antibody titer Peripheral blood mononuclear cells PBMC isolated from these subjects will be evaluated for the following 1 central and effector memory T cell responses including their proliferative responses and cytokine production profiles by flow cytometry 2 IFN-gamma production by ELISPOT following specific antigenic stimulation 3 measurement ex vivo of the frequency of circulating influenza-specific T cells by using commercially available MHCtetramers andor MHCpentamers and flow cytometry and 4 role of regulatory T cells in the modulation of influenza responses in the elderly Studies for measurement ex vivo of the frequency of circulating influenza-specific T cells by using commercially available MHCtetramers andor MHCpentamers and flow cytometry will concentrate on IFN-gamma a cytokine shown by many investigators to play a central role in the host immune response to influenza antigens If promising results are observed other cytokines eg IL-12 TNF-alpha might also be evaluated in future investigations if sufficient cells and resources are available Major factors involved in the decision to concentrate these studies on IFN-gamma include the need to remain focus in a defined set of scientific questions and the fact that we will only have access to a limited number of peripheral blood mononuclear cells PBMCs that might preclude the study of additional cytokines
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
False
Is an FDA AA801 Violation?:
None