Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky delivers opening statement during a Senate hearing on Health, Education, Labor and Pensions on “Next Steps: The Way Forward for the COVID-19 Response” on Capitol Hill in Washington, D.C. November 4th. , 2021.
Elisabeth Franz | Reuters
CDC director Rochelle Walensky said on Tuesday that the US population has enough immunity to provide some protection against the more contagious sub-variant of omicron BA.2, which could help prevent a new wave of Covid hitting hospitals.
“A high level of population immunity from vaccines, boosters and previous infection will provide some level of protection against BA.2,” Walensky said during a Covid briefing at the White House. White House chief medical adviser Dr. Anthony Fauci said last month that infections could rise because of BA.2, but he doesn’t expect a new surge.
BA.2 currently accounts for 72% of circulating Covid variants in the US, according to the Centers for Disease Control and Prevention. It quickly supplanted an earlier version of the omicron, BA.1, which caused a massive wave of infection during the winter. In early February, BA.2 represented about 1% of Covid variants in the US.
BA.2 is now the dominant variant of Covid in every region of the country, with the highest circulation occurring in the densely populated northeast, the recurring epicenter of the pandemic in the US. BA.2 accounts for over 80% of circulating variants in New England. , New York, New Jersey, Puerto Rico and the Virgin Islands, according to the CDC.
As of December, an estimated 95% of the U.S. population aged 16 and over had developed antibodies against the virus, either through vaccination or infection, according to a CDC review of donated blood samples. However, simply having antibodies against the virus does not necessarily stop the infection. Omicron, with its many mutations, has an increased ability to infect both vaccinated and previously infected people.
However, according to the study, people who have been vaccinated, revaccinated and recovered from a previous infection have a high level of protection against hospitalization for AD.2. published by scholars in Qatar associated with Weill Cornell Medicine in Doha. The study was not peer-reviewed.
The scientists found that people who received three Pfizer shots had the highest protection against hospitalization from BA.2 at 98%. People who received two doses of Pfizer and those who recovered from a previous infection had the same level of protection from hospitalization, 76% and 73%, respectively. People who received two doses of Pfizer and recovered from a breakthrough infection were 97% protected.
The data suggests that even if BA.2 triggers an increase in infections in the US, there may be enough immunity in the population to prevent a major outbreak of severe illness that overwhelms hospitals.
According to the UK and Danish health authorities, BA.2 is transmitted 30-80% more often than the earlier version of omicron. Scientists from the UK, South Africa and elsewhere found that BA.2 generally did not cause more severe illness in humans than BA.1, which was less severe than the delta variant.
BA.2 has caused outbreaks in Europe, including in the UK and Germany. China is fighting the worst wave since 2020, locking down major cities like Shanghai.
However, Covid infections in the US are now stable, even as BA.2 makes up a growing proportion of the virus variants circulating around the country. The U.S. averaged about 25,000 new infections on Monday, down 4% from a week earlier, according to CDC data. However, new infections are likely underreported as many people use home tests that are not counted in the data.
The number of people hospitalized with Covid has fallen to its lowest level since 2020. More than 10,700 patients were hospitalized with the virus on an average of seven days on Tuesday, a 92% decrease from the peak of the omicron wave in January, according to the data. from the Department of Health and Human Services.
The CDC has adjusted its Covid guidance to focus more on hospitalizations as a measure of how badly the virus is affecting a country. More than 97% of the US population lives in counties with low to moderate Covid rates, meaning people there do not need to wear masks under CDC guidance.