SAN FRANCISCO -- Earlier in the pandemic, experts had hoped if we can get 75% of Americans vaccinated, we can contain the coronavirus. Thursday, we're at just over 50% vaccinated. But 75% is no longer ...

Johnson & Johnson said Thursday that new data shows that its single-shot COVID-19 vaccine provides protection against the virus for at least eight months and effectively prevents infection from ...

Moderna on Tuesday released preliminary data indicating its vaccine is likely to hold up against several variants of concern, including the Delta variant, which is predicted to become the dominant ...

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.

WASHINGTON -- National Institutes of Health Director Dr. Francis Collins said Sunday he believes vaccine requirements could make a difference in slowing the rapid spread of COVID-19 and acknowledged ...

Vaccine effectiveness against COVID-19 infection dropped from 91% to 66% once the delta variant accounted for the majority of circulating virus, according to a study published Tuesday by the U.S.

The delta variant is fueling the COVID-19 surge in the United States, but experts warn that a more dangerous variant could emerge if more Americans don't get vaccinated. Delta is the most recent of ...

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 ...

Recently, Dr. Anthony Fauci said the delta variant of the novel coronavirus is the greatest threat to eliminating COVID-19 we have seen yet. The highly contagious variant, which was first found in ...

SAN FRANCISCO (KGO) -- A surge in coronavirus cases has been reported in the Bay Area and across California as well as the country due in part to the emergence of the highly-contagious delta variant.