The body’s defenses lose flexibility and diversity over time, and protective responses to vaccines weaken as well. Scientists are working on ways to boost seniors’ protections against influenza, the novel coronavirus and other pathogens.
FIVE BIG QUESTIONS: Research has yielded a parts list of the genes and cell types involved in development. Now it’s time for the computationally intensive task of figuring out how they interact to form a living being.
For decades, genetics and biochemistry have formed the bedrock of developmental biology. But it turns out that physical forces — the way cells push, pull and squeeze each other — play a huge role, too.