A concerning variant is about to become dominant in the US, experts say, and how Americans act could help fuel or curb a surge

Experts are worried some Americans are letting up too early -- at a critical time when looming dangers are threatening to wipe out the progress the US has made in its battle against Covid-19. At least a dozen state leaders have eased Covid-19 restrictions this month, often citing improving Covid-19 trends and growing vaccination numbers. At the same time, air travel is hitting pandemic-era records and the first spring break crowds have begun descending on Florida and other sunny regions while cases of a dangerous variant are on the rise.