The US has done an about-face on its approach to the coronavirus pandemic this week. Masks are back, vaccine mandates are looming, and officials are sounding more worried than they have in months.

SAN FRANCISCO -- The Delta variant now accounts for more than 51% of new COVID-19 cases across the country. Los Angeles County public health officials recommend everyone wear masks inside regardless ...

Differing strains of the coronavirus continue to appear around the world and a new COVID-19 variant, the so-called "Delta" variant, has health experts concerned. The variant, otherwise known as B.1617 ...

The Centers for Disease Control and Prevention listed the COVID-19 delta variant as one of its "variants of concern" (VOCs) on June 15. According to the CDC, VOCs can be more contagious, more ...

The delta coronavirus variant surging across the United States appears to cause more severe illness and spread as easily as chickenpox, according to an internal document from the US Centers for ...

The Centers for Disease Control and Prevention listed the COVID-19 delta variant as one of its "variants of concern" (VOCs) on June 15. According to the CDC, VOCs can be more contagious, more ...

LOS ANGELES - As cases of the novel coronavirus and its delta variant continue to increase, a new projection model shows there are no signs of the hyper-contagious variant slowing down — foreshadowing ...

While the delta COVID-19 variant is the dominant strain in the U.S., it’s now officially the dominant strain worldwide “by far,” officials from the World Health Organization said during a Sept. 21 ...

An internal Centers for Disease Control and Prevention document obtained by several news outlets warns that the COVID-19 delta variant could be more likely to produce severe illness and can spread as ...