As the delta variant of coronavirus continues to spread across the world, a relative of the deadly strain is sparking concerns among health officials in South Korea, one of several countries to record ...

LONDON — A newly-discovered mutation of the delta variant is being investigated in the U.K. amid worries that it could make the virus even more transmissible and undermine Covid-19 vaccines further.

The new Omicron variant of coronavirus, with its many mutations and seemingly quick spread in South Africa, is worrying scientists and government officials. But doctors want to remind Americans that ...

The Delta variant, also referred to as a "double mutant" because it carries two mutations, is 55 per cent more transmissible ...

The Delta variant is an increasing source of concern for health experts as vaccinations wane and the holiday weekend approaches in the U.S. Those at the highest risk are unvaccinated individuals and ...

The sighting and monitoring of any new COVID-19 variant—this time it’s CH.1.1—must be given context, experts say. However, despite the new variants, the U.S. continues to move toward a place where it ...