A third of COVID in the US is now caused by Omicron BA.2 with total cases declining

People still wear their masks amid the coronavirus (COVID-19) pandemic, in Los Angeles, California, US, February 8, 2022. REUTERS/David Swanson

(Reuters) – One in three coronavirus cases in the United States is now caused by the Omicron BA.2 subtype of the coronavirus, government data showed on Tuesday. Record highs in January.

Although the highly contagious sub-variants that have also been seen in other countries are emerging, US health experts say a large wave of new infections here seems unlikely.

COVID-19 infections in the US have fallen sharply since January, although a resurgence in parts of Asia and Europe has raised fears that one could follow in the US given previous patterns during the two years of the pandemic.

In the Northeast, including New Jersey, New York and Massachusetts, Omicron BA.2 now makes up more than half of the cases, according to data from the US Centers for Disease Control and Prevention (CDC).

The CDC said it represented 35% of infections in the United States for the week ending March 19. That compares with 22.3% for the week ending March 12, which was revised down from 23.1%, according to the CDC model estimating proportions of circulating variables.

Dr. Anthony Fauci, one of the top US infectious disease officials, said at a Washington Post event Tuesday that he doesn’t think there will be a significant increase anytime soon, “unless something changes dramatically.”

However, Fauci noted that cases in the US are generally about three weeks behind the UK, “so if we’re going to see a slight increase, we should start seeing it within the next week or so.”

There is no evidence yet that a higher BA.2 indicates an increase in cases, said Daniel Koretzkes, chief of infectious diseases at Brigham and Women’s Hospital in Boston.

“I think the only concern and where people need to remain vigilant is that as we loosen many of the restrictions around concealment and gathering, there is a potential opportunity for BA.2 or another species to gain a foothold,” Koretzkes said.

The World Health Organization (WHO) said the sub-variant is more transmissible than the Omicron BA.1 variant that caused the massive winter increase. The World Health Organization said it does not appear to cause more serious disease, and early data showed that infection with BA.1 provides strong protection against reinfection with BA.2.

As of March 19, the seven-day moving average for US COVID-19 cases was 27,747, down nearly 18% from the previous week.

Most of the country is considered to be at low transmission of COVID, according to new CDC guidelines introduced last month that emphasized the hospital’s caseload capacity. Most people were advised that they no longer need to wear masks indoors. Read more

There is no evidence of a wave in the sewage

The University of Washington’s Institute for Health Metrics and Evaluation (IHME), which updated its closely watched forecast on Monday, does not expect a significant increase in coronavirus cases in the United States in the coming weeks.

“However, it is possible that a rapid return of pre-COVID-19 behavior and the spread of BA2 could see a short period of increased case numbers,” tweeted Ali Mokdad, a professor at the University of Washington.

Testing of coronavirus wastewater samples has proven to be an effective early measure of upcoming increases in COVID-19 cases, sometimes detecting a spike in new infections days or even weeks before human testing data.

Biobot Analytics has been testing wastewater around the United States for the virus since March 2020, and is currently monitoring more than 200 sites in about 40 states.

“So far, there is no evidence of a wave in the wastewater data,” said Mariana Matos, CEO of Biobot Analytics.

“Just to give an idea of ​​context, the level of virus in wastewater was about 100 times higher during the first Omicron wave in December than it is now,” Matos said.

New York City is moving forward with dropping more mitigation plans. Mayor Eric Adams said Tuesday that masks will now be optional for 2- to 4-year-olds in schools and daycare facilities starting April 4.

The seven-day positivity rate in New York City schools was 0.15% last week, according to the city’s Department of Education. The city’s seven-day positivity rate for all ages was 21% at the height of the last rush.

“Our schools have been among the safest places for our children since the start of the pandemic, and we will not rescind this requirement unless science says it is safe to do so,” Adams said in a statement.

Additional reporting by Hanvi Satija and Ankur Banerjee in Bengaluru, Michael Ehrman in New Jersey and Brendan O’Brien in New York; Additional reporting by Manujna Madipatla and Manas Mishra in Bengaluru; Editing by Amy Karen Daniel and Bill Bercrot

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