The COVID mRNA vaccine generates enough of an antibody response to protect against severe disease for six months. But other vaccines offer years-long — even lifelong — immunity, as is the case with the measles and yellow fever vaccines.
This contrast led Bali Pulendran, a professor of pathology and microbiology and immunology at the Stanford University School of Medicine, to wonder: Why? Why are some vaccines only able to stimulate immunity for a few months, but others last a lifetime?
Now, his team at Stanford Medicine has an answer.
Through this basic research question, Pulendran and a team at Stanford Medicine uncovered a major insight involving megakaryocytes, cells located in human bone marrow.
Megakaryoctyes are responsible for creating platelets, which play a crucial role in blood clotting. And, as the team discovered, megakaryocytes appear to play a role in immunity by creating a hospitable environment for B-cells. B-cells are essential for stimulating an immune response after vaccination. They do so by producing antibodies, which recognize and fight germs.
The thinking is, vaccines that are better able to activate megakaryocytes should also stimulate an immune response for a longer period of time.
"If you could understand the immunology underlying these effects, then surely we could apply that immunological insight to devising new vaccines," he told NPR's Short Wave podcast.
The team published these findings in the journal Nature Immunology this month.
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This episode was produced by Rebecca Ramirez and Megan Lim. It was edited by Rebecca Ramirez and Christopher Intagliata. Tyler Jones checked the facts. Additional reporting by Regina Barber. The audio engineers were Jimmy Keeley and Neil Tevault.
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