BA.2 Accounts for More than Half of New US Cases, CDC Estimates


according to estimates From the Centers for Disease Control and Prevention on Tuesday, the highly contagious Omicron subvariant known as BA.2It is now the dominant version of the virus in new US cases, which caused an increase in coronavirus cases in Europe.

World Health Organization last week repeated was BA.2 dominant version Omicron worldwide and CDC director Dr. Rochelle Walensky predicted it would dominate in the United States soon.

The scientists are tracking BA.2, one of three genetically distinct strains of the Omicron variant of the coronavirus, discovered by South African researchers in November.

BA.2 (previous value) first identified It accounted for about 55 percent of new U.S. cases in the U.S. in December and in the week ending Saturday. CDC estimates Tuesday. Figures are rough estimates, subject to revision as more data become available. as are In late December, when the agency had to significantly reduce its estimate of the nationwide prevalence of the BA.1 Omicron variant. Before that, the Delta variant had been raided since July.

Omicron cases can only be confirmed by genetic sequencing, which is performed on only a fraction of samples nationwide. CDC’s estimates vary in different parts of the country. BA.2 was found in a high proportion of samples in the Northeast and a lower proportion of samples in the Midwest and Great Plains.

BA.1, predominant in late Decemberwas almost entirely responsible for the record-breaking increase in US cases this winter, but earlier this year BA.2 began to account for a larger proportion of new infections. It is attributed to its rapid growth partly due to eight mutations in the gene For the spike protein on the surface of the virus, which is absent in BA.1.

While BA.2 is more contagious than BA.1, it has not been shown to cause more serious illness and vaccines continue to protect against the worst outcomes. Many US health officials We expect the number of cases to increase without a big surge caused by BA.2but other scientists worry the nation isn’t doing enough to prevent another possible surge.

In the US, the seven-day average of new cases dropped significantly from the height of the Omicron BA.1 increase. While the decline has slowed in recent days, the average has hovered around 30,000 cases per day last week, the level last seen in July, according to one report. New York Times database.

Hospitalizations due to coronavirus have dropped nearly 35 percent in the past two weeks to about 18,000 per day. Hospitalizations in the intensive care unit also decreased by about 42 percent, falling below 3,000.

And about 750 coronavirus deaths It’s reported every day in the US, and that’s the lowest daily average since the Omicron variant went live late last fall. The last time the rate was this low was in mid-August.

The rise of BA.2 in some European countries came at the same time as the rise in new cases. in the Asia-Pacific region, Hong Kong, South Korea and New Zelandall of which have suffered relatively less damage than previous variants, are now blocked by BA.2.

Experts have said repeatedly that vaccines continue to protect people, especially those who are supported, against serious illness. Throughout the BA.1 rise, vaccines continued to be highly effective against hospitalizations, and it appears to have been during the BA.2 rise.



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