Tfh Dysfunction in HIV and Aging

Who May Qualify: 1. For HIV positive participants: - HIV infection, as documented by any licensed ELISA test kit. Participants on ART as a result of prior HIV documented infection will not be required to provide proof of diagnosis of HIV infection. - Additional criteria for HIV positive 1. on ART for at least 1 year. Occasional viral blips up to 1000 copies/ml also acceptable provided the patients are on continuing treatment, 2. Cluster of differentiation 4 (CD4) count available in the prior 6 months and \>200/mm3 3. Undetectable viral load (\< 40 copies/mL). Blips of \<1000 copies/mL will be allowed. 2. For HIV negative participants: - Documented negative HIV test at the time of study entry, either by any licensed ELISA. 3. For all participants: 1. Individuals age: ≤35 years and ≥65 years. 2. No history of other weakened immune system disorders 3. Not on steroid or other immunosuppressive/immunomodulators medications. 4. No active malignancies. 5. Agreeable to receive both regular standard (STD-TIV) and high dose (HD-TIV) influenza vaccination. 6. Agreeable to participate in study for a complete course of study full visits including 2 consecutive flu seasons. 7. Able to provide willing to sign a consent form. Exclusion criteria 1. Contraindication to receive influenza vaccination. 2. Non-adherence to ART for HIV positive 3. Unable to provide willing to sign a consent form. 4. Influenza vaccination already given during the current vaccination season. 5. Known drug abuse including cocaine by history Always talk to your doctor about whether this trial is right for you.