Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center. More recent studies — but not all — show waning effectiveness of the mRNA vaccines to prevent ...

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 ...

As the highly contagious Delta variant of COVID-19 continues to surge in populations with low vaccination rates, doctors are looking more closely at the origins of another variant. The Epsilon variant ...

Researchers in several countries including the U.S. have found a new variant of the virus that causes COVID-19. Still, the Deltacron variant, made from a combination of genes found in Delta and ...

The proportion was estimated at approximately 3% in late May. A highly contagious variant of the novel coronavirus that was initially identified in India now accounts for about 58% of all COVID-19 ...

People infected with the Omicron variant of the coronavirus SARS-CoV-2 are almost 50% more likely to infect those they live with than are individuals infected with the Delta variant, a detailed ...