Memory B Cell Subset Found to Predict Immunity After Flu Vaccination

University of Alabama at Birmingham and Emory University researchers have identified a distinct subset of memory B cells that predict long-term immunity after influenza vaccination in humans. Effector memory B cells are essential to provide long-term immunity after vaccination or infection. In a study published in the journal Immunity, the team identified a novel subset of memory B cells by the presence of the FcRL5 receptor protein on the cells' surface. This novel subset is transcriptionally and epigenetically different from all previously described memory B cell subsets.

FcRL5+ T-bet+ memory B cells can be detected seven days after immunization, and the presence of these cells correlates with vaccine antibody responses months later. This makes it an early, easily monitored cellular compartment that can predict the development of a long-lived antibody response to vaccines. The discovery of these cells could help develop effective yearly influenza vaccines, as these cells may represent a new way to predict influenza vaccine durability.

The most effective vaccines induce formation of long-lived plasma cells and memory B cells. Plasma cells reside in bone marrow and make protective antibodies that can be found in the blood, while memory B cells live for many years in the lymph nodes and in tissues like the lungs. The FcRL5+ T-bet+ memory B cells are transcriptionally like effector-like memory cells and express transcriptional, epigenetic, and metabolic functional programs that poised these cells for antibody production.

These findings provide a new way to predict influenza vaccine durability, potentially allowing researchers the ability to test flu vaccines closer to flu season. This discovery could ultimately result in the development of a more effective flu vaccine, which could save countless lives worldwide.