CDC says COVID-19 cases in U.S. may be 10 times higher than reported

The true number of Americans who've been infected with COVID-19 may top 20 million, according to new estimates from the Centers for Disease Control and Prevention. The assessment comes from looking at blood samples across the country for the presence of antibodies to the virus. For every confirmed case of COVID-19, 10 more people had antibodies

Why have 14,000 people volunteered to be infected with coronavirus?

Imagine being told to inhale a nasal spray full of coronavirus. More than 14,000 people in the U.S. and elsewhere are putting their names forward to do so. They are volunteering for what's called a "human challenge trial," an ethically controversial way to test vaccines that would deliberately infect people with a virus that has killed over 270,000 people worldwide and has no cure.