Several months ago, Stanford immunologist Mark Davis, PhD, went for a stroll in Union Cemetery in Redwood City, Calif. (not far from the Stanford campus). Graves there date from the Civil War-era and Davis, who's currently immersed in a study of childhood immunity, was intrigued.
"In the early years, you see entire families — mom, dad, and then a whole bunch of children's headstones," Davis told me. "It really brought home to me how differently we live now that we just take for granted a kid will survive and grow up."
Vaccines arrived and childhood survival rates soared. Yet young children remain much more vulnerable to infectious diseases than adults. Why?
Davis and his team think vaccines trigger a set of changes that strengthens children's immune systems -- allowing them to ward off diseases they haven't even heard of before. That's why the researchers are conducting a group of studies, all focused on revealing new details about the immune system's response to the flu vaccine. They need participants, particularly young children who have never received a flu vaccine before. They also need older children and twins. All participants will receive a licensed flu vaccine that will help protect from influenza this coming winter.
Davis and colleagues plan to investigate the children's development of two types of immune cells — memory T and B cells — that are specialized to recognize certain foreign invaders. Interestingly, adults have T cells that spot diseases they've never been exposed to, such as HIV, Davis said. Yet newborns lack these specialized cells, leaving them vulnerable to infection.
"Somewhere between birth and adulthood we see the appearance of these memory T cells without having the particular disease," Davis said. "It's a real puzzle."
Davis suspects that routine vaccines and infections may spur the development in children of a broad spectrum of memory T cells, ones that recognize all sorts of diseases. One study plans to follow children for several years, perhaps revealing how, and when, the children develop a full compliment of these memory T cells, Davis told me.
The studies are possible thanks to the development of new analytical techniques, according to virologist and immunologist Harry Greenberg, MD, who is working with Davis on the influenza studies.
"We've been studying influenza for half a century, but these new assays developed in the last five years offer hope we can develop better ways of protecting more people," Greenberg told me.
More information about the flu vaccine studies and the Stanford-LPCH Vaccine Program is available here or (650) 498-7284.
Becky Bach is a proud graduate of the UC Santa Cruz Science Communication Program (go Banana Slugs!) and a science-writing intern at the Office of Communications and Public Affairs.
Previously: Q&A about enterovirus-D68 with Stanford/Packard infectious disease expert, Gut bacteria may influence effectiveness of flu vaccine and Side effects of childhood vaccines are extremely rare, new study finds
Photo by Gabriel Metsu