• The WHO said Monday that it has categorized seven variants "of interest" and three variants "of concern" that it is following at a global level.
• Variants of concern, the more serious designation, include B.1.1.7, the strain first identified in the U.K. that is currently the most prevalent strain in the U.S.; B.1351, first identified in South Africa, and P.1, first identified in Brazil.
• "The information is coming in fast and furious," the WHO's Maria Van Kerkhove said. "There are new variants every day that are being identified and being reported, not all of which are important."

The World Health Organization is closely following 10 coronavirus variants "of interest" or "of concern" across the world, including two that were first detected in the U.S. and a triple-mutant variant that's wreaking havoc in India, as potential global public health threats.

New Covid-19 strains pop up every day as the virus continues to mutate, but only a handful make WHO's official watchlist as a "variant of interest" or the more serious designation "variant of concern," which is generally defined as a mutated strain that's more contagious, more deadly and more resistant to current vaccines and treatments.

The organization has classified three strains as variants of concern: B.1.1.7, which was first detected in the U.K. and is the most prevalent strain currently circulating throughout the U.S.; B.1.351, first detected in South Africa, and the P.1 variant, first detected in Brazil.

One variant of interest is the B.1617 variant, or triple-mutant strain, first found in India, but the WHO's technical lead for Covid-19, Maria Van Kerkhove, said more studies are needed to completely understand its significance.

"There actually are a number of virus variants that are being detected around the world, all of which we need to properly assess," Van Kerkhove said. Scientists look at how much each variant is circulating in local areas, whether the mutations change the severity or transmission of the disease and other factors before categorizing them as a new public health threat.

"The information is coming in fast and furious," she said. "There are new variants every day that are being identified and being reported, not all of which are important."

Other variants classified as variants of interest include B.1525, which was first detected in the U.K. and Nigeria; B.1427/B.1429, first detected in the U.S.; P.2, first detected in Brazil; P.3, first detected in Japan and the Philippines; S477N, first detected in the U.S., and B.1.616, first detected in France.

Van Kerkhove said the classifications are determined, at least in part, by sequencing capacities, which vary by country. "It's really patchy so far," she said.

She said the agency is also looking to local epidemiologists as an extension of the agency's "eyes and ears" to better understand the situation on the ground and identify other potentially dangerous variants.

"It's important that we have the proper discussions to determine which ones are significant from a public health value, meaning does it change our ability to use public health social measures, or any of our medical countermeasures," she said.

"We are putting the right people together in the room to discuss what these mutations mean," she said. "We need the global community to be working together, and they are."

The Centers for Disease Control and Prevention also has a list of four variants of interest and five variants of concern that is similar to the WHO's list, though the CDC primarily focuses on variants that are causing new outbreaks in the United States.

Van Kerkhove said a number of countries "have some worrying trends, some worrying signs of increasing case numbers, increasing hospitalization rates and ICU rates in countries that don't yet have access to the vaccine, who have not reached the coverage levels that are needed to really have that impact on severe disease and death and on transmission."