Heterosubtypic Immune Responses to Influenza in Older People (NCT00798343) | Clinical Trial Compass
CompletedPhase 1
Heterosubtypic Immune Responses to Influenza in Older People
United Kingdom292 participantsStarted 2009-01
Plain-language summary
Vaccination is the principal means of combating epidemic and pandemic influenza. As vaccines induce relatively strain-specific and short-lived antibody responses, annual immunisation with regularly updated vaccine is recommended for seasonal influenza, but would not be expected to protect against a pandemic event. In clinical trials among young adults, at least two doses of avian influenza H5 or H9 subunit vaccine are needed to induce moderate antibody responses. However, studies including older subjects have unexpectedly found that some people aged over 65 yrs have pre-vaccination neutralising antibody to influenza H5 and H9 respectively. These subjects mount a robust antibody response to single dose H5 or H9 pandemic vaccine, suggesting that they are effectively primed to at least some strains of avian influenza.
This exploratory proposal focuses on those elderly subjects whose immune systems already exhibit antibodies to H5 with a goal of investigating the humoral and cellular basis of the immune response to seasonal and pandemic vaccination. We will examine neutralising antibody responses to a range of human and non-human influenza viruses before and after seasonal and pandemic vaccination and evaluate cellular B and T cell immune responses before and after pandemic H5 vaccination
Who can participate
Age range18 Years
SexALL
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Inclusion criteria
✓. Subjects aged over 18 years of age, mentally competent, who have signed an informed consent form after having received a detailed explanation of the study protocol;
✓. Subjects willing to be enrolled in the vaccine study if appropriate from prescreening blood test results
✓. In good health as determined by:
✓. medical history,
✓. physical examination,
✓. clinical judgment of the Investigator;
✓. Able to understand and comply with all study procedures and to complete study diaries, can be contacted, and will be available for study visits
Exclusion criteria
✕. Receipt of another investigational agent within 4 weeks, or before completion of the safety follow-up period in another study, whichever is longer, prior to enrollment and unwilling to refuse participation in another clinical study through the end of the study;
✕. Subjects who experienced any acute disease or infection requiring systemic antibiotic or antiviral therapy (chronic antibiotic therapy for urinary tract prophylaxis is acceptable) within the past 7 days before Visit 1 or any visit where trial vaccination is planned;