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 ...

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is associated with less severe acute disease and reduced risk of hospitalization as compared to the previously dominant ...

Data are needed regarding the effectiveness of a third dose of a messenger RNA (mRNA) vaccine against the B.1.1.529 (omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ...

Scientists have worked extensively hard to contain the coronavirus disease (COVID-19) pandemic caused by the rapid transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). They ...