COVID-19 infections and hospitalizations in the U.S. are on the rise as the highly contagious delta variant spreads, driven by the least vaccinated parts of the country. And while no vaccine is ...

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 ...

More than 99.99% of people fully vaccinated against Covid-19 have not had a breakthrough case resulting in hospitalization or death, according to the latest data from the US Centers for Disease ...

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 ...

In the early days of the coronavirus vaccine rollout, scientists were hopeful it might herald the long-awaited turning point of the pandemic, not only bringing the threat of severe disease, ...

A growing proportion of COVID-19 deaths are occurring among the vaccinated, a new ABC News analysis of federal data shows. In August of 2021, about 18.9% of COVID-19 deaths occurred among 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 ...