These parts of the US could become 'breeding grounds' for potentially more Covid-19 variants, expert says
Fewer than half of US states have reached the White House's July 4th vaccine goal as the Delta variant threatens the nation's progress
It's time to rethink 'one-size-fits-all' approach to mask guidance, expert says, as Delta variant is spotted in every US state
Fauci warns there may soon be 'two Americas' as divide widens between vaccinated and unvaccinated areas
