Covid-19 cases fall to new lows in the US. But unvaccinated children are a 'vulnerable host' for the virus, expert says
The slowing Covid-19 vaccination rate is worrying experts. Here's what some states are doing to change the trend
Californians can soon go maskless at work -- if every worker in a room is fully vaccinated, safety board says
Caught in a 'pickle,' tens of millions of Americans might not have had an adequate response to the Covid-19 vaccine
