Of any state, California has the most to lose if the U.S. Supreme Court overturns the Affordable Care Act. Health care coverage for millions of people is at stake, as are billions in federal dollars

A national lockdown as Covid-19 cases tick up is "a measure of last resort," the co-chair of Joe Biden's coronavirus taskforce, Vivek Murthy, said Sunday.

Americans can expect that about 25 to 30 million people could be vaccinated each month afterward, said Moncef Slaoui, co-lead of Operation Warp Speed.

Pfizer Inc PFE.N has launched a pilot delivery program for its experimental COVID-19 vaccine in four U.S. states, as the U.S. drugmaker seeks to address distribution challenges facing its ultra-cold storage requirements

A rapid finger-prick test designed to show whether a person has previously been infected with SARS-CoV-2 is significantly less accurate than earlier research suggested, scientists report in a new study.

Who will be the first to get COVID-19 vaccines? No decision has been made, but the consensus among many experts in the U.S. and globally is that health care workers should be first, said Sema Sgaier of the Surgo Foundation, a nonprofit group working on vaccine allocation issues. An expert panel advising the U.S. Centers ...