The coronavirus is always evolving. While some varieties appear to fade, leaving small ripples of surges in their wake, others have continued to drive massive outbreaks.

According to experts, a new variant of the virus, BA.2.12.1, is fast spreading and will likely become the dominant form of the virus in the United States within the next few weeks. There is currently no evidence that this causes more severe disease.

The Centers for Disease Control and Prevention revealed that BA.2.12.1 accounted for nearly 36% of all new cases in the US in the week ending Saturday. This is up from 26% of cases the previous week and 16% of infections during the second week of April.

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Fastest strain 

BA.2.12.1, which was discovered in the US by New York State health officials in April, is spreading faster than the early forms of the Omicron strain, which caused a massive rise in infections over the winter. This form is a descendant of BA.2 and appears to have spread much faster, for unknown reasons. 

The virus appears to be discovering new methods to spread. In an interview on Wednesday, Krista Queen, director of viral genomics and surveillance at Louisiana State University, stated that "Omicron was more transmissible than Delta, which was more transmissible than Alpha." "That's why it's taking over now, especially in the Northeast," she says, adding that BA2.12.1 is building on that trend.

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New cases have climbed in New York, though they remain well below the horrifying numbers seen earlier in the pandemic. Nonetheless, a handful of counties have become hotspots, warning state health officials that the coronavirus will not go away despite widespread pandemic fatigue.

Dr. Queen anticipates that rising infections will spread from the Northeast to the South and then to the West, causing more outbreaks. "We're already seeing it here in Louisiana," said Dr. Queen, who handles the virus's genetic analysis at the institution. "Our most recent community sample sequencing runs have all been BA.2.12.1, and those samples are from mid-April."

Spike in infections

According to a New York Times database, the number of new cases reported in the US has more than doubled in the last month as Omicron subvariants have spread. Cases have surged by 50 percent in the last two weeks.

However, because the availability of at-home tests has risen and the findings are frequently not formally reported, reported cases are likely an undercount of the virus's true spread.

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Nonetheless, preliminary research reveals that BA.2.12.1 evades the body's immune defenses more adeptly than prior generations of the coronavirus, which may account for its rapid dissemination. "It'll be everywhere in two weeks," said Massimo Caputi, a biomedical science professor at Florida Atlantic University.

But the subvariant is finding more opportunities as well. Taj Azarian, a genomic epidemiologist at the University of Central Florida, said he believes the recent surge is mostly due to “the great unmasking.”

“We’re in this phase of pandemic fatigue and complacency,” he said. “And while we need to balance the weight of mental health with the risk of contraction, as a result, we’ve seen an uptick not only in the Omicron variant but other respiratory illnesses.”

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