In recent weeks, there have been frequent reports about the rise of the more transmissible Omicron subvariant BA.2 around the world.
BA.2 now makes up nearly all the new cases in Denmark, the U.K., Switzerland, Sweden, India, Belgium, Norway, South Africa, The Philippines, Hong Kong and many more regions.
Throughout the first few weeks of the year, however, as it spread rapidly abroad, BA.2 did not see significant growth in the United States.
No longer.In the second and third weeks of March, the percentage of new U.S. cases sequenced that were attributed to BA.2 was nearly 1 in 4, or 23%.
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