Continuing their swift march across the United States, Omicron sub-variables known as BA.4 and BA.5 have come together to dominate among new coronavirus cases, according to new estimate on Tuesday from the Centers for Disease Control and Prevention.
As of the week ended Saturday, BA.4 accounted for 15.7% of new cases and BA.5 was 36.6%, representing about 52% of new cases in the United States, numbers experts say that will increase in the coming weeks .
The statistics, released Tuesday morning, are model-based and may be revised as more data becomes available, which occurred in late December, when the agency estimated miss.
In less than six months since BA.4 and BA.5 were first detected in South Africa, the two subvariables appearing in the United States surpassed the previous two Omicron subvariables, including BA.2, to be popular version for some time early this spring. The other, BA.2.12.1, is dominant as of the week ending June 18, according to CDC estimates. During the winter, the form of Omicron that first appeared in the United States caused the number of cases to skyrocket. Before that, the Delta . variant dominated in the United States since early summer.
BA.4 and BA.5 represent the qualities of artists on the run, able to eliminate certain antibodies produced after vaccination and coronavirus infections, including infections caused by some previous versions of Omicron that caused. That might explain why these extra variables spread faster than the rest of the Omicron family. But There is not much evidence yet that they cause more severe disease.
Subvariables BA.4 and BA.5 have been discovered around the world, and they promote increase in cases in South Africa in the spring, though pre-existing immunity for viruses. The wave was not as high as South Africa’s previous waves and the death toll did not increase sharply. Just last week, South Africa abolish its rules require masks in indoor public spaces.
In recent weeks, an average of more than 100,000 new coronavirus cases have been reported in the United States each day, According to the New York Times databasea number that represents only a fraction of the real number. Many infections go uncounted in official reports. Some scientists estimate that the current wave of cases is the second largest of any pandemic.
As of Monday, U.S. hospitalizations are 6 percent increase over the past two weeks, averaging more than 31,000 per day, according to federal data. Data from state and local health authorities show the number of new deaths at an average of less than 400 people per day. It’s part of the thousands seen daily in the winter peak of Omicron.
“But in my mind, 250 deaths a day is still too much,” said Dr. Rochelle Walensky, director of the CDC, said last week in Aspen, Colo. “The deaths we are seeing are the elderly in general, people who are sick, have many comorbidities, people who have received many vaccines or who have not been vaccinated. “
Many Americans with risk factors say they feel ignored and abandoned as the government and their neighbors have sought to return to normal.
As always, the spread of the virus is a matter of the region. In the Northeast and Midwest, known cases have been declining for weeks, while in the South and West, cases are increasing.
Nationwide, public health rules continue to be lifted, including ending on Saturday of the indoor masking mission for Alameda County, the second most populous county of the San Francisco Bay Area. In New York City, Broadway Theater – save for one – will remove their mask requirements starting Friday. Even the long-standing requirement to get tested for coronavirus before flying to the US from abroad fell this month.
While the recent availability of vaccines for children aged 6 months to 5 years is a welcome development for many parents and day care centers, experts do not expect availability Pediatric dosing to change the overall trajectory of the pandemic in the United States.
The natural weakness The vaccine’s ability to protect against infection over time, together with the immune evasion capabilities of BA.4 and BA.5, may explain why these minor bacteria can spread so quickly. fast. It is also urgent for evolution Omicron targeting boosters. While vaccine manufacturers have raced to develop thesethey are based on other versions of Omicron and it is not clear how well they can protect against BA.4 and BA.5 infections.
Preliminary evidence from laboratory research suggests that unvaccinated people who have been infected with the Omicron version, known as BA.1, can easily be reinfected by BA.4 or BA.5. Research shows that vaccinated people are likely to get slightly better fares.
But as the virus evolves, no one can tell if retooled vaccines might become obsolete by the time they become available.
“What we don’t know is what will happen with a new vaccine in the fall,” Dr. Walensky said while in Aspen. “I think we’re going to need more vaccines.”