Functional Consequences of T-bet Expression in Flu-specific Memory B Cells After Live Attenuated Influenza Vaccine (LAIV)

As yet the investigators do not understand if there are biomarkers of immune protection after the Flumist or Live Attenuated Flu Vaccine (LAIV). Here the investigators test the hypothesis that the T-bet expressing fraction of flu-specific B cells after live attenuated influenza vaccination also serves as an early biomarker of long-lived antibody responses after vaccination. In this study the investigators will be providing the LAIV to up to 10 healthy subjects and assaying their immune response and then providing the intramuscular influenza vaccination and testing to see if the immune protection after the LAIV also protects after the intramuscular influenza vaccination. Update: We have amended this protocol to study the antigen-specific B cell populations that circulate after LAIV or IIV prime and LAIV or IIV boost.

Previously (1) the investigators established that a fluorochrome labeled reagent with the influenza antigen hemagglutinin accurately identified flu-specific B cells after inactivated influenza vaccination and we established that a subset of these flu-specfiic B cells that express the lineage defining master transcriptional regulator, T-bet, correlate with long lived antibody responses. As yet the investigators do not understand if there are biomarkers of immune protection after the Flumist or Live Attenuated Flu Vaccine (LAIV). Here the investigators test the hypothesis that the T-bet expressing fraction of flu-specific B cells after live attenuated influenza vaccination also serves as an early biomarker of long-lived antibody responses after vaccination. In this study the investigators will be providing the LAIV to up to 10 healthy subjects and assaying their immune response and then providing the intramuscular influenza vaccination and testing to see if the immune protection after the LAIV also protects after the intramuscular influenza vaccination. Update: We have amended this protocol to study the antigen-specific B cell populations that circulate after LAIV or IIV prime and LAIV or IIV boost.