MARIN COUNTY, Calif. -- As the Delta variant spreads, we are learning more about breakthrough COVID-19 cases. Numbers from California's state health department help put into perspective what the ...

LAS VEGAS, NEVADA -- A California couple says they were fully vaccinated, but still contracted COVID-19 while on vacation as experts say breakthrough cases are possible, especially with the delta ...

Professional sports leagues are uniquely positioned to track breakthrough Covid cases because they test thousands of athletes consistently, according to Dr. Robby Sikka, a physician who has worked ...

With the more contagious delta variant strain of COVID-19 spreading throughout the country, hospitalizations and deaths from the virus are on the rise. According to the Centers for Disease Control and ...

NEW YORK -- As Americans brace for the possibility of another difficult winter ahead in the nation's fight against coronavirus, there is a renewed sense of urgency to get as many people inoculated and ...

The more contagious Delta variant of Covid-19 now makes up 83% of sequenced samples in the United States, US Centers for Disease Control and Prevention Director Dr. Rochelle Walensky said Tuesday.