Why next year's flu shot might not be as good as it should be

A scientist at the Centers for Disease Control and Prevention, in an Atlanta laboratory, wears a protective air-tight suit when handling samples of influenze.

America's withdrawal from the World Health Organization is affecting the ability of U.S. scientists to track flu and other pathogens. That could be a blow to the development of the 2025 flu vaccine.

(Image credit: Centers for Disease Control/Smith Collection/Gado)