Why the Omicron BA.5 subsidiary is a big deal

But suddenly many people who had recovered from Covid-19 as recently as March or April found themselves exhausted, coughing and staring at two red lines on a rapid test. How could this happen again – and so soon?

The culprit this time is yet another offshoot of Omicron, BA.5. It has three key mutations in its spike protein that make it both better at infecting our cells and more adept at bypassing our immune defenses.

Laboratory studies of antibodies in the blood of people vaccinated or recovered from recent Covid-19 infections have looked at how well they resist BA.5, and this subvariant may outwit them. So people who had Covid as recently as winter or even spring may again be vulnerable to the virus.

“We don’t know the clinical severity of BA.4 and BA.5 compared to our other Omicron subvariants,” CDC Director Dr. Rochelle Walensky said during a briefing on Tuesday. White House Covid-19 Response Team. “But we know it’s more transmissible and more immune. People who are already infected, even with BA.1 and BA.2, are probably still at risk for BA.4 or BA.5.”

A “full” wave

The result is that we are getting sick en masse. As Americans have shifted to faster home testing, official case numbers — currently hovering around 110,000 new infections a day — reflect only a fraction of the true disease burden.

“We estimate that for every reported case, there are 7 unreported,” wrote Ali Mokdad, professor of health metrics science at the Institute for Health Metrics and Evaluation at the University of Washington, in an email.

Other experts believe the surge could be up to 10 times higher than currently reported.

“We are probably looking at almost a million new cases a day,” Dr. Peter Hotez said on CNN on Monday. “It’s a full wave of BA.5s that we’re experiencing this summer. It actually looks worse in the Southern states, just like 2020, just like 2021,” said Hotez, dean of the National School. of tropical medicine at Baylor College of Medicine in Houston.

This puts us within the range of cases reported during the first Omicron wave, in January. Remember when it seemed like everyone was getting sick everywhere at the same time? This is still the situation in the United States.

This may not seem like a big deal, as vaccines and better treatments have dramatically reduced the risk of death from Covid-19. Yet around 300 to 350 people die on average each day from Covid-19, enough to fill a large passenger jet.

Underreported Covid-19 cases leave US in blind spot as BA.5 variant becomes dominant

“It’s unacceptable. It’s too high,” Dr. Ashish Jha, the White House’s Covid-19 response team coordinator, said during Tuesday’s briefing.

Daily hospitalizations are also climbing in the United States. The fraction of patients requiring intensive care has increased by around 23% over the past two weeks. And other countries are also experiencing BA.5 waves.

“I am concerned that Covid-19 cases continue to rise, putting further strain on health systems and strained health workers. I am also concerned about the upward trend in deaths” , said Tedros Adhanom Ghebreyesus, director general of the World Health Organization. , at a press conference on Tuesday following the agency’s decision to maintain its emergency declaration for Covid-19.

The pandemic, he said, is “far from over”.

What are the challenges of continued propagation

There are also more insidious health risks to consider. A recent pre-print study that compared the health of people who had been infected with Covid-19 one or more times found that the risk of new and sometimes lasting health problems increased with each subsequent infection, suggesting that reinfections are not not necessarily benign.

Although vaccination reduces the risk of contracting long Covid, a certain percentage of people have long-lasting symptoms after a breakthrough infection.

Covid-19 reinfections may increase the likelihood of new health problems

This is another reason why the high number of Covid-19 cases is a big problem: because the virus is still spreading wildly, it has every chance of mutating to create even more adapted and infectious versions of itself. -same. It’s doing it faster than we can change our vaccines, leaving us stuck in the rehearsal period of the pandemic’s Covid flush.

On Tuesday, Dr. Anthony Fauci, director of the National Institutes of Allergy and Infectious Diseases, pleaded with Americans to use all tools available to stop the spread of the virus, including masking, ventilation and social distancing.

“We need to keep virus levels as low as possible, and that’s our best defence. If a virus isn’t replicating and spreading very robustly, that gives it less chance of mutation, which which gives it less chance of another variant evolving,” Fauci said during a press briefing.

In fact, it is already happening.

Meet BA.2.75

Even as the United States accepts BA.5, variant hunters around the world are keeping a close eye on another Omicron descendant, BA.2.75. It has been detected in a dozen countries, including the United States, and seems to be growing rapidly in India.

BA.2.75 has nine changes in its tip region that distinguish it from BA.2 and about 11 changes from BA.5, according to Tom Peacock, a virologist at Imperial College London.

Several of BA.2.75’s mutations are in a region of the spike protein known to be an important place for antibodies to bind to stop the virus, said Ulrich Elling, a scientist at the Austrian Academy of Sciences who monitors the coronavirus variants for that country. .

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There is little information to go on: it is still unclear, for example, how BA.2.75 can compete with BA.5 or if it causes more serious disease. But experts say it has all the hallmarks of a variant that could go global.

“It’s already spread to many different countries, so we know it has some kind of resistance,” said Shishi Luo, associate director of bioinformatics and infectious diseases for Helix Labs, which decodes virus samples. for the CDC and other customers.

Because of that, and because of the changes in the region of the virus that our antibodies are looking for to stop it, “we kind of know in advance that this one is going to cause problems,” Luo said.

Based on what we know now, she expects this subvariant could lead to a fall surge of Covid-19 in the United States.

In the meantime, Jha said, people should have boosters available to them to keep their immunity as strong as possible. US health officials have stressed that people who are boosted now will still be able to get an updated vaccine this fall that includes the BA.4 and BA.5 strains.

Jha specifically urged Americans 50 and older, “if you haven’t gotten a shot this year, go get one now. It could save your life,” he said.

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