This is the first story of a five-part series diving into the rise of the anti-vaccine political movement.

A Biden administration that vowed to restore Americans' faith in public health has grown increasingly paralyzed over how to combat the resurgence in vaccine skepticism.

And internally, aides and advisers concede there is no comprehensive plan for countering a movement that's steadily expanded its influence on the president's watch.

The rising appeal of anti-vaccine activism has been underscored by Robert F. Kennedy Jr.'s insurgent presidential campaign and fueled by prominent factions of the GOP.