Why Omicron’s sect BA.5 was so big

Laboratory studies of antibodies from the blood of people vaccinated or recovered from a recent Covid-19 infection are investigating how well they can tolerate BA.5, and this submutant can defeat them. I can. Therefore, people who had Covid recently even in winter or spring may be vulnerable to the virus again.

“We don’t know the clinical severity of BA.4 and BA.5 compared to other Omicron submutants,” said CDC Director Dr. Rochelle Walensky on Tuesday at the White House Covid-19 Response Team. Said in the briefing. “But we know that it is more contagious and immune-avoidant. Even with BA.1 and BA.2, previously infected people are at risk of BA.4 or BA.5. It may still be. “

“Full on” wave

As a result, we are sick in the crowd. The official number of cases (currently about 110,000 new infections per day) reflects only a small fraction of the actual disease burden as Americans switch to faster home tests. ..

“We estimate that there are seven unreported cases for every reported case,” wrote Ali Mokudad, a professor of health indicator science at the Institute for Health Metrics, University of Washington, in an email.

Other experts believe that the waves can be 10 times higher than currently reported.

“We’re probably seeing nearly a million new cases a day,” Dr. Peter Hotez told CNN on Monday. “This is the full wave of BA.5 we are experiencing this summer. In fact, it’s getting worse in the southern states, like in 2020 and in 2021.” Hotez, Dean of the National School of Tropical Medicine, said. Baylor College of Medicine in Houston.

This allows us to put us in a series of cases reported during the first Omicron wave in January. Do you remember when everyone everywhere seemed to get sick at the same time? That is also the situation in the United States.

It may not seem like a big deal, as vaccines and better treatments have dramatically reduced the risk of death from Covid-19. Still, Covid-19 kills an average of about 300-350 people each day, enough to fill a large jet airliner.

“It’s unacceptable, too expensive,” Dr. Ashishger, coordinator of the Whitehouse Covid-19 Response Team, said in a briefing on Tuesday.

Daily hospitalizations are also increasing in the United States. The proportion of patients requiring intensive care has increased by about 23% in the last two weeks. And other countries are also experiencing the wave of BA.5.

Tedros Adhanom Gebreyes, Director of the World Health Organization, said: At a news briefing on Tuesday after the agency’s decision to maintain the Covid-19 state of emergency.

According to him, the pandemic is “far from the end.”

Things that are in danger due to continuous spread

There are also more insidious health risks to consider. Recent preprint studies comparing the health status of people infected with Covid-19 more than once show that each subsequent infection increases the risk of new and sometimes persistent health problems, and reinfection is not always benign. It is suggested that there is no such thing.

Vaccination reduces the risk of Covid’s prolongation, but a percentage of people show persistent symptoms after a breakthrough infection.

This is another reason why the large number of cases of Covid-19 is a major problem. The virus is still so prevalent that it has the opportunity to mutate to create a more appropriate and infectious version. This is faster than changing the vaccine and stays in the pandemic Covid-rinse-repeat period.

On Tuesday, Dr. Anthony Fauci, director of the National Institute for Allergic Infectious Diseases, told Americans to use all the tools available to stop the spread of the virus, including masking, ventilation, and social distance. I begged for.

“You need to keep the level of the virus as low as possible. This is the best defense. If the virus is not replicated and spread very robustly, the chances of mutation are low and another variant evolves. There is a possibility of doing it. “

In fact, this is already happening.

Meet BA.2.75

Even if the United States agrees to BA.5, variant hunters around the world are closely watching another Omicron descendant, BA.2.75. It has been detected in about 10 countries including the United States and seems to be growing rapidly in India.

According to Tom Peacock, a bachelor of arts at Imperial College London, there are nine changes in the spike area of ​​BA.2.75 that differ from BA.2, and about 11 changes compared to BA.5.

Some of the mutations in BA.2.75 are in the region of peplomers, where the antibody is known to be an important place to bind to block the virus, and Austria monitors the country’s coronavirus mutants. Ulrich Elling, a scientist at the Academy of Sciences, said. ..

There is little information to go on. For example, it is not yet known how BA.2.75 competes with BA.5 or whether it causes a more serious illness. But experts say it has all the characteristics of a variant that can be global.

Shishi Luo, Associate Director of Bioinformatics and Infectious Diseases at Helix Labs, which decodes virus samples from the CDC and other clients, said:

So, and because of the changes in the area of ​​the virus that our antibodies are looking to shut it down, “I know in advance that this will cause some problems,” Luo said.

Based on what we now know, she predicts that this subvariety could cause the Fall Covid-19 wave in the United States.

Meanwhile, Jha said people should get boosters available to them to keep their immunity as strong as possible. US health officials have emphasized that currently boosted people will also have the latest shots, including BA.4 and BA.5 strains, available this fall.

Jha specifically told Americans over the age of 50, “If you haven’t been vaccinated this year, get it now. You can save your life.”