Characterization of Humoral and Cellular Immune Responses Elicited by Influenza Vaccination in Healthy Adults

  • End date
    Apr 14, 2027
  • participants needed
  • sponsor
    University of Pennsylvania
Updated on 14 November 2021
influenza vaccination
trivalent influenza vaccine
Accepts healthy volunteers


Cellular and humoral immune responses before and after seasonal influenza vaccination will be assessed. Each year, up to 100 participants will be enrolled. To study age-specific differences in immune responses, participants with various years of birth will be enrolled. The investigators hypothesize that humans with different birth years will mount antibody and cellular responses of different specificities following seasonal influenza vaccination.


The investigators and others have shown that the first influenza virus someone is exposed to leaves an immunological imprint that affects antibody responses to antigenically related influenza strains later in life. Year of birth can therefore be used to predict influenza virus exposures during the first years of life. It is possible that immune responses to influenza vaccination later in life differ between people with different birth years, depending on what virus someone was "imprinted" with. This could result in birth year differences in antibody responses upon vaccination and vaccine effectiveness. However, the effect of year of birth on the specificity of humoral and cellular immune responses elicited by influenza vaccination has not been studied in depth. In this study, the investigators will measure influenza virus cellular and humoral immune responses in individuals of different birth years before and after influenza vaccination.

Condition Influenza
Treatment Seasonal influenza vaccine
Clinical Study IdentifierNCT05108818
SponsorUniversity of Pennsylvania
Last Modified on14 November 2021


Yes No Not Sure

Inclusion Criteria

Provision of signed and dated informed consent form
Stated willingness to comply with all study procedures and availability for all study visits
Aged 18 years and older
In good health based on self-reported medical conditions via an online survey

Exclusion Criteria

Known allergic reactions to components of the study vaccine
Known latex allergy
History of severe reactions following previous immunization with licensed or unlicensed influenza virus vaccines
History of GBS within 6 weeks of receipt of a previous influenza vaccine
Immunosuppression as a result of an underlying illness or treatment with immunosuppressive or cytotoxic drugs, or use of anticancer chemotherapy or radiation therapy within the preceding 36 months
Treatment with immunoglobulin or another blood product within the 3 months prior to enrollment in this study
Active neoplastic disease (excluding non-melanoma skin cancer or prostate cancer that is stable in the absence of therapy) or a history of any hematological malignancy ("active" is defined as having received treatment within the past 5 years)
Long-term (greater than 2 weeks) usage of oral or parenteral steroids, or high-dose inhaled steroids
Administration of an influenza vaccine within 2 months prior to enrollment
Known acute or chronic medical condition that, in the opinion of the investigator or appropriate sub-investigator, would render vaccination unsafe or would interfere with the evaluation of responses
Participation in a study that involves an experimental agent or having received an experimental agent (other than a COVID-19 vaccine) within 1 month prior to enrollment or expecting to receive another experimental agent during the study period
Intends to donate blood during the study period
Any condition that would, in the opinion of the site investigator, place the subject at an unacceptable risk of injury or render the subject unable to meet the requirements of the protocol
Known human immunodeficiency virus, hepatitis B, or hepatitis C infection
Any condition that the principal investigator believes may interfere with successful completion of the study
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