mRNA-based influenza vaccine expands breadth of B cell response in humans.

Eliciting broad and durable antibody responses against rapidly evolving pathogens like influenza viruses remains a formidable challenge. The germinal center (GC) reaction enables the immune system to generate broad, high-affinity, and durable antibody responses to vaccination. mRNA-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines induce persistent GC B cell responses in humans.

'Persistent germinal center responses: slow-growing trees bear the best fruits'.

Germinal centers (GCs) are key microanatomical sites in lymphoid organs where responding B cells mature and undergo affinity-based selection. The duration of the GC reaction has long been assumed to be relatively brief, but recent studies in humans, nonhuman primates, and mice indicate that GCs can last for weeks to months after initial antigen exposure. This review examines recent studies investigating the factors that influence GC duration, including antigen persistence, T-follicular helper cells, and mode of immunization.