Health

New variants will keep COVID-19 circulation at high levels through summer, experts say

New variants will keep COVID-19 circulation at high levels through summer, experts say
Written by admin_3fxxacau

Even as the United States grapples with its latest wave of COVID-19, new research suggests variants on the horizon could keep case levels high. The next influx of infections will likely come from the new omicron BA.4 and BA.5 subvariants, two closely related viruses that were first characterized in South Africa and landed in the United States around the end of March. according to the GISAID gene sequence sharing site. These variants are gaining ground against BA.2, especially in the central part of the country. Recent research suggests that they escape the immunity created by vaccines and past infections. According to the latest updates from the US Centers for Disease Control and Prevention and genomics company Helix, BA.4 and BA.5 together accounted for about 6% 7% of new infections in the United States at the end of May. “This is a serious threat,” wrote Dr. David Ho, professor of microbiology and immunology at Columbia University in New York, in an email. “Only a month ago it was 0.02%. BA.4 has been detected in at least 30 countries and BA.5 has been sampled in 32 countries, according to the Outbreak.info website, which is managed by the Scripps Research Institute.Ho and his co-authors recently tested antibodies from the blood of vaccinated and boosted people, as well as antibodies from people who had recovered from breakthrough COVID-19 infections, against BA viruses. .4 and BA.5 modified in the lab. In each case, they found a drop in potency against BA.4 and BA.5. They found that the BA.4 and BA.5 viruses are more than four times more likely to evade antibodies in people who have been vaccinated and boosted against BA.2 viruses More breakthrough infections All this means that BA.4 and BA.5 are more likely to lead to breakthrough infections, even in people who have already had COVID-19.Without improved vaccines or boosters, Ho expects many Americans s will fall ill in the coming weeks. “I think we’ll see lots of infections, but not necessarily more serious illnesses or deaths,” he said. Ho’s research is published as a preprint, which means it has not been reviewed by outside experts or published in a medical journal. which is ahead of the United States in its BA.4/BA.5 cycle, has seen infections increase but has not seen a corresponding increase in deaths, said Shishi Luo, associate director of bioinformatics and diseases infections at Helix. we are extrapolating from South Africa what we will see in the US is that BA.4 and BA.5 will increase as this has competitive advantages over existing strains but fingers crossed , this is not going to lead to more serious problems results, ”said Luo. One question variant hunters have asked is whether BA.4 and BA.5 can outperform BA.2.12.1, the highly contagious strain that is currently the leading cause of COVID-19 infections in the United States. These branches of the omicron family tree rose to prominence around the same time; BA.2.12.1 quickly took over the United States while BA.4 and BA.5 established themselves in South Africa. They share some similarities, including changes at location 452 in their genome, a genetic address known to help variants evade our immunity. Viruses clash “It’s like boxing,” said Dr. Alex Greninger, deputy director of the University of Washington’s Clinical Virology Laboratory. “It’s like the national champion of South Africa taking on the national champion of the United States.” You don’t know how to rank them if they’ve never fought,” he says. But BA.4 and BA.5 have against BA.2.12.1 in other parts of the world, like the UK. There, scientists found that the time needed to double the number of infections caused by one variant was about 5.5 days for BA.2.12.1 and about a day less for BA.4 and BA.5, indicating that these viruses spread faster. Doubling times were included in a recent technical report from the UK Health Security Agency. “The betting favorite now suggests that BA.4 and BA.5 would be able to remove BA.2.12.1,” Greninger said. Ho and his team believe they may have figured out what gives BA.4 and BA.5 that extra edge. In addition to all the changes in other variants help them ignore our vaccines, these viruses have passed an F486V mutation.This is a big change that helps disguise them from our immune system. ire. In the past, this had a downside: it made the virus spike less likely to bind to our cells, so they were less competitive. But BA.4 and BA.5 have an additional mutation, called R493Q, which restores their ability to bind to cells, restoring their ability to infect us. Although BA.4 and BA.5 seem capable of mastering BA.2.12.1, they have not competed in the United States, and the fitness of these varieties depends very much on the playing field. The variations do not follow a rule book. But for the next few months, experts say, there will just be plenty of COVID-19 around us. “For the summer, before the winter, I expect these viruses to have come out at relatively high levels,” Greninger said. “Just the number of cases, the pure disruptions to the workforce — it’s just a very high disease burden.”

Even as the United States grapples with its latest wave of COVID-19, new research suggests variants on the horizon could keep case levels high.

The next influx of infections will likely come from the new omicron BA.4 and BA.5 subvariants, two closely related viruses that were first characterized in South Africa and landed in the United States around the end of March. , according to the Gene Sequence Sharing Site. GISAID.

These variants are gaining ground against BA.2, especially in the center of the country. Recent research suggests that they escape the immunity created by vaccines and past infections.

According to most recent updates from the United States Centers for Disease Control and Prevention and the Genomics Society HelixBA.4 and BA.5 together accounted for about 6-7% of new infections in the United States at the end of May.

“This is a serious threat,” wrote Dr. David Ho, professor of microbiology and immunology at Columbia University in New York, in an email. “Just a month ago it was 0.02%.”

BA.4 has been detected in at least 30 countries and BA.5 has been sampled in 32 countries, according to the Outbreak.info website, which is operated by the Scripps Research Institute.

Ho and his co-authors recently tested antibodies from the blood of vaccinated and boosted people, as well as antibodies from people who had recovered from breakthrough COVID-19 infections, against the modified BA.4 and BA.5 viruses. in laboratory. In each case, they found a power drop against BA.4 and BA.5.

They found that BA.4 and BA.5 viruses are more than four times more likely to evade antibodies in vaccinated and vaccinated people than BA.2 viruses.

No more breakthrough infections

All of this means that BA.4 and BA.5 are more likely to cause breakthrough infections, even in people who have had COVID-19 before.

Without improved vaccines or boosters, Ho expects many Americans to fall ill in the coming weeks or months. “I think we will see a lot of infections but not necessarily more serious illnesses or deaths,” he said.

Ho’s research is published as a preprintmeaning it has not been reviewed by outside experts or published in a medical journal.

South Africa, which is ahead of the United States in its BA.4/BA.5 cycle, saw infections rise but did not experience a corresponding increase in deaths, said Shishi Luo, associate director of the bioinformatics and infectious diseases at Helix.

“So I think if we extrapolate from South Africa, what we will see in the United States is that BA.4 and BA.5 will increase, because they have competitive advantages over existing strains, but let’s cross our fingers, it’s not going to lead to more serious results,” Luo said.

One question variant hunters have asked is whether BA.4 and BA.5 can outperform BA.2.12.1, the highly contagious strain that is currently the leading cause of COVID-19 infections in the United States.

These branches of the omicron family tree rose to prominence around the same time; BA.2.12.1 quickly took over the United States while BA.4 and BA.5 took hold in South Africa.

They share some similarities, including changes at location 452 in their genome, a genetic address known to help variants evade our immunity.

Viruses collide

“It’s like boxing,” said Dr. Alex Greninger, associate director of the University of Washington’s Clinical Virology Laboratory. “It’s like the national champion of South Africa taking on the national champion of the United States.

“You don’t know how to classify them if they’ve never fought,” he says.

But BA.4 and BA.5 opposed BA.2.12.1 in other parts of the world, such as the UK. There, scientists found that the time needed to double the number of infections caused by one variant was around 5.5 days. for BA.2.12.1 and about a day less for BA.4 and BA.5, indicating that these viruses spread faster. Doubling times have been included in a recent technical report from the UK Health Security Agency.

“The betting favorite now suggests BA.4 and BA.5 could knock out BA.2.12.1,” Greninger said.

Ho and his team think they may have figured out what gives BA.4 and BA.5 an extra advantage.

In addition to all the changes in other omicron variants that help them bypass our vaccines, these viruses have passed an F486V mutation. This is a great change that helps disguise them from our immune system. In the past, this had a downside: it made the virus spike less likely to bind to our cells, so they were less competitive. But BA.4 and BA.5 have an additional mutation, called R493Q, which restores their ability to bind to cells, restoring their ability to infect us.

Although BA.4 and BA.5 seem capable of dominating BA.2.12.1, they have not faced each other in the United States, and the fitness of these varieties depends very much on the playing field. The variants do not follow a rule book.

But for the next few months, experts say, there will just be plenty of COVID-19 around us.

“For the summer, before the winter, I expect these viruses to be at relatively high levels,” Greninger said. “Just the number of cases, the pure disruption to the workforce – it’s just a very high disease burden.”

#variants #COVID19 #circulation #high #levels #summer #experts

About the author

admin_3fxxacau

Leave a Comment