mRNA vaccines broaden the immune response against influenza

An mRNA vaccine against seasonal influenza stimulates a broader and more durable immune response than traditional vaccines. This innovative approach enables the immune system to produce antibodies capable of recognizing a wider range of viral strains, including those that evolve rapidly.

In healthy adults, the mRNA vaccine caused a marked increase in specific antibody levels against type A and B viruses. Unlike conventional vaccines, it also maintained prolonged activity in the lymph nodes, where essential immune reactions occur. These reactions, called germinal centers, allow B cells to adapt and refine their ability to neutralize the virus over time.

Researchers observed that germinal centers remained active for at least six months after vaccination in some participants. This persistence promotes increased antibody diversification, meaning the body develops a more extensive immune memory. The antibodies produced after this vaccine showed an enhanced ability to bind to various influenza strains, even those that are genetically different from the strains targeted by the vaccine.

Additionally, the mRNA vaccine stimulated existing memory B cells while recruiting new ones. This led to an expansion of antibody clones, with each clone representing a family of cells capable of producing slightly different antibodies. This increased diversity within existing clones strengthens the immune system’s ability to adapt to new viral variants.

Analyses also revealed that the antibodies induced by this vaccine had a better ability to neutralize a wide range of influenza strains. This suggests that this technology could offer broader protection, reducing the need to reformulate the vaccine each year to keep up with viral evolution.

This advancement paves the way for more effective vaccines capable of protecting against current and future influenza strains while limiting the impact of annual viral mutations. It could also inspire the development of universal vaccines against other constantly evolving pathogens.

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DOI: https://doi.org/10.1038/s41590-026-02569-5

Title: mRNA-based influenza vaccine expands the B cell response breadth in humans

Journal: Nature Immunology

Publisher: Springer Science and Business Media LLC

Authors: Hanover C. Matz; Tae-Geun Yu; Kritika Dixit; Caroline Kikawa; Julian Q. Zhou; Garazi Pena Alzua; Lowrey Peyton; Anders Madsen; Fangjie Han; Ariana Ghez Farrell; Robert Hoelzl; Aaron J. Schmitz; Stephen C. Horvath; Hunter K. Keplinger; Benjamin S. Strnad; Mark J. Hoegger; William D. Middleton; Michael K. Klebert; Nina H. Lin; Raffael Nachbagauer; Florian Krammer; Robert Paris; Jesse D. Bloom; Jackson S. Turner; Rachel M. Presti; Jiwon Lee; Ali H. Ellebedy