That's how the so-called "deltacron" variant — a mashup of delta and omicron — came to be. This process of recombining tells us a lot about the possible past and future of SARS-CoV-2.

It's a sibling of the first omicron variant that swept the world. Is it more contagious? Does it cause severe disease? Will it keep current omicron surges going? Researchers are looking for answers.

The World Health Organization deemed it a variant of concern, and the U.S. is banning travel from parts of Africa where it's spreading. Here's what scientists know and what they're trying to learn.

(Image credit: Phill Magakoe)

Here's what we know about the effectiveness of vaccines for variants of concerns, notably the delta variant, first identified in India and now responsible for more than 20% of new U.S. cases.

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The new names won't replace the scientific names already assigned to new variants, but the WHO said it's making the change to help avoid fueling stigma toward nations where new variants arise.

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One of the hottest areas of research right now: studies to determine how well current vaccines work against emerging coronavirus "variants of concern."

(Image credit: Jeff Pachoud)

One day you're worrying about the regular old coronavirus. Then — seemingly out of the blue — there are variants. Worrisome variants! How did they come to be? And why are they likely more contagious?