Bali Pulendran’s lab at Emory Vaccine Center teamed up with UCSD researchers and recentlyÂ published a huge analysis of immune responses after seasonal flu vaccinationÂ (Immunity is making it available free this week, no subscription needed). Hundreds of volunteers at the Vaccine Center’s Hope Clinic took part in this study.
Note — this study looked at antibody responses to flu vaccines, but didn’t assess protection: whether study participants actually became sick with flu or not.
ThreeÂ points we wanted to call attention to:
*Long-lasting antibodiesÂ AÂ surprising finding was how the “molecular signatures” that predict the strength of the immune response a few weeks after vaccination did not predict how long anti-flu antibodies stayed around.Â Instead, a separate set of signatures predicted the durability of antibody levels.
These distinct signaturesÂ may beÂ connected with how plasmaÂ cells, responsible for antibody production, need to findÂ homes in the bone marrow. That sounds like the process highlighted by Eun-Hyung Lee and colleagues in an Immunity paper published in July. In bone marrow samples from middle-aged volunteers, her team had found antibody-secreting cells that surviveÂ from childhood infections.
*Interfering (?) activation of NK cells/monocytes in elderlyÂ While the researchers found people older than 65 tended to have weaker antibody responses to vaccination, thereÂ wereÂ common elements of molecular signatures that predicted strong antibody responses in younger and older volunteers.Â However, elderly volunteers tended to have stronger signatures from immune cells that are not directly involved in producing antibodies (monocytes and â€˜natural killerâ€™ cells), both at baseline and after vaccination.
From the discussion: “This indicates a potential connection between the baseline state of the immune system in the elderly and reduced responsiveness to vaccination.” Additional comments on this from Shane Crotty in Brad Fikes’ article for the Union Tribune.
*The mountain of dataÂ from this and similar studies is available for use by other researchers on the web site ImmPort.