A new study from a team from Emory Vaccine Center provides insights into why the flu vaccine’s immunity is shorter than other vaccines… The home base for immune cells that produce antibodies is the bone marrow. Because long-term serum antibody levels are maintained by bone marrow plasma cells (BMPC), the researchers investigated the production and maintenance of these cells after influenza vaccination.
“We were able to follow the specific cells produced by the vaccine because they produced unique antibodies that can be identified using sequencing techniques,” said Carl Davis, PhD, first author of the paper and a postdoctoral fellow in Ahmed’s laboratory.
“We could see that these new antibodies expanded in the bone marrow one month after vaccination and then contracted after one year. On the other hand, antibodies against influenza that were in the bone marrow before the vaccine was given stayed at a constant level over one year.”
“What this shows is that just getting to the bone marrow is not enough,” Ahmed said. “A plasma cell has to find a niche within the bone marrow and establish itself and undergo gene expression and metabolism changes that promote longevity.”
The findings are expected to inform the design of proposed longer-lasting “universal” flu vaccines. Strategies to enhance the persistence of BMPCs will be important for the next-generation of influenza vaccines.