Intradermal Influenza Vaccination

In order to be eligible to participate in this study, an individual must meet all of the following criteria: 1. Provision of signed and dated informed consent form 2. Stated willingness to comply with all study procedures and availability for the duration of the study, as well as have deidentified samples and data stored for future research. 3. Able to proficiently speak, read, and write English. 4. Male or female, aged 18-40 years old at time of initial enrollment a. Participant is allowed to participate in subsequent influenza seasons even if they will be \>40 years old. 5. In good general health as evidenced by medical history Individuals meeting any of the following criteria will be excluded from study participation: 1. CBC with differential, lymphocyte phenotyping with T, B, and natural killer cells (TBNK), complete metabolic panel, anti-CMV immunoglobulin (Ig) G and IgM, and/or anti-Epstein-Barr virus (EBV) antibody panel values outside of the Yale Department of Laboratory Medicine normal reference ranges and deemed clinically significant by the PI at the time of screening. 2. Positive result for anti-HIV 1/2 antibody screening at the time of screening. 3. Prior receipt of a current seasonal influenza vaccine (for the season of participation). 4. History of allergy or hypersensitivity to any components of the study vaccine (e.g., egg protein). 5. History of severe reactions to vaccines. 6. Use of an oral glucocorticoid within the past 30 days. 7. Receipt of a liv…