New fast and stealthy Covid-19 variants are poised to fuel a winter surge

New fast and stealthy Covid-19 variants are poised to fuel a winter surge
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A flurry of new Covid-19 variants appears to be gaining ground globally, raising fears of a winter surge.

In the United States they are BQ.1, BQ.1.1, BF.7, BA.4.6, BA.2.75 and BA.2.75.2. In other countries, the XBB recombinant variant has increased rapidly and appears to be fueling a new wave of cases in Singapore. Cases are also on the rise in Europe and the UK, where these variants have taken hold.

Dr. Peter Hotez, who co-directs the Center for Vaccine Development at Texas Children’s Hospital, says he thinks of them collectively as variants of Scrabble because they use letters that score high on the board game like Q, X and B.

As the US heads into fall, Covid-19 cases are on the decline. Normally, that would be a reason for hope that the nation could escape the waves of the past two pandemic winters. But virus experts fear the downward trend may soon reverse, thanks to this herd of new variants.

Together, the variants accounted for nearly 1 in 3 new COVID-19 infections nationwide last week, according to the latest estimates from the US Centers for Disease Control and Prevention.

Updated bivalent booster vaccines and antiviral drugs such as Paxlovid are expected to continue to provide protection against severe outcomes of Covid-19 infections caused by the new variants.

But the new variants are particularly devastating for millions of Americans who have weakened immune systems. new research suggests that changes to these variants make them impervious to the latest lab-created antibodies available to help treat and prevent severe cases of covid-19, and the US government has run out of money to incentivize the creation of new ones .

It is unclear if this gang of new variants will continue to run together, each sharing a piece of the covid-19 infection pie, or if one will outperform the others, as it has in previous waves.

Though each descended from slightly different branches of the Omicron family tree, these new offspring have evolved to share many of the same mutations, a phenomenon known as convergent evolution.

Some experts think that this convergence means that we have entered a new phase of the virus’s evolution, one that will see several variants circulating at the same time.

“What is likely to happen is that we have several co-circulating semi-dominant lineages going into the winter season,” said Nathan Grubaugh, an associate professor of epidemiology at the Yale School of Public Health.

“That’s because with convergent evolution, perhaps several different lineages can independently gain similar levels of transmissibility against a single new variant taking over.

“This is predominantly the case with most pathogens, such as influenza and RSV,” Grubaugh wrote in an email. “Now that the virus has adapted fairly well to human transmission, most of what is circulating has a high fitness.”

Maria Van Kerkhove, technical lead for Covid-19 response for the World Health Organization, said on Wednesday that the large mix of new variants was becoming more difficult for the WHO to assess because countries were reducing their surveillance.

“So we have to be prepared for this. Countries need to be in a position to carry out surveillance, to deal with surges in cases and perhaps to deal with surges and hospitalizations. We still don’t see a change in gravity. And our vaccines are still effective, but we have to remain vigilant,” she said.

For now, Omicron’s BA.5 subvariant still ranks first in the US. According to CDC estimates, it caused about 68% of new infections in the US last week, but several sublineages New ones are rapidly outperforming it, particularly BQ.1 and BQ.1.1.

Each of the BQs caused only 6% of new infections in the US last week, but in recent weeks, the proportion of new Covid-19 infections caused by these viruses has doubled every six to seven days, a rapid growth rate compared to BA.5, which is already a highly fit virus, says Dr. Anthony Fauci, who heads the National Institute of Allergy and Infectious Diseases.

And these are just two of the new crop of Omicron descendants who are making a move.

“Projections vary a little bit, but overall, most people feel that by mid-November they will end up being a substantial proportion and have eliminated BA.5 as the dominant variant,” Fauci told CNN.

These variants are different from BA.4 and BA.5, but are descended from those viruses, the result of genetic drift. So they share many parts of their genomes with that virus.

Its changes are not on the scale of what happened when the original Omicron burst onto the scene in November 2021. That strain of the virus, now long gone, came out of the left genetic field, leaving researchers and public health officials struggling to catch up

Fauci says that this time, we’re as ready as we could be for the latest batch of variants.

“It’s not so different from BA.5 that it would completely escape the protection that you would get from the vaccine” if people just got vaccinated, Fauci said.

The booster bivalent vaccine, authorized in September, protects against the original strain of the coronavirus as well as against the BA.4 and BA.5 subvariants.

“We have an updated bivalent BA.5 vaccine as a booster that we are pushing people to do. It is compared to the still dominant variant which is BA.5 and it will almost certainly have a reasonably good degree of cross-protection against BQ.1.1 and the others and yet the uptake of these vaccines as we are in the middle October, it’s disappointing,” he said.

According to the latest data from the CDC, 14.8 million people have received an updated bivalent booster six weeks after the promotion campaign. That’s less than 10% of the population that is eligible to get one.

The poor uptake of the new boosters, combined with the immune evasion of the new variants and declining population immunity, is almost certainly a recipe for increased cases and hospitalizations in the coming weeks.

“It will probably be significantly larger than wave BA.5, at least that’s what I’m hoping for,” said Mark Zeller, a project scientist who monitors variants at the Scripps Research Institute. But Zeller says he doesn’t expect this winter’s surge to reach the heights of January’s Omicron wave.

Hotez says that people should not panic over this news, but should pay attention.

“We underperform as a nation with people getting their bivalent boosters,” Hotez said.

The genetic changes these variants share appear to help them escape immunity created by past vaccinations and infections, a recipe for reinfections and advanced infections, particularly for people who haven’t had an updated booster.

Crucially, some of the variants also appear to be impervious to the latest lab-made antibodies available to stave off serious Covid-19 infections: an antibody treatment called bebtelovimab, made by Eli Lilly, and the combination of two long-acting antibodies. . in Evusheld, an injection made by AstraZeneca that helps keep immunocompromised people from getting sick.

If these antibodies stop working against the virus, the United States will still have COVID-19 antiviral drugs like Paxlovid, molnupiravir and remedsivir to help those at risk of serious complications.

But antibody therapies are especially important for people whose immune function has been weakened by medications, disease or age. These are the same people whose bodies do not respond strongly to vaccinations.

Antibodies are also needed to help people who can’t take antiviral therapy because of possible drug reactions.

White House COVID-19 Response Coordinator Dr. Ashish Jha says the federal government has been spurring the development of new monoclonal antibodies during the pandemic by promising to purchase new therapies once they are manufactured.

The government can no longer do that, he said, because Congress has refused to approve additional funding for the Covid-19 response.

As a result, the development of new antibodies and other new therapies is behind schedule.

“So even if we got the money today, it would take us many months to bring a monoclonal to market, and we don’t have the money today anyway,” Jha told CNN.

Jha said that means the nation heads into the fall and winter with a smaller arsenal against the virus, just when it needs to expand its options.

“There is no monoclonal session ready to go tomorrow that we can buy off the shelf,” he said.

Antibodies are a losing proposition for companies because millions of dollars of investment are needed to make them and because the virus is evolving so fast they might be effective for only a few months.

“That’s a terrible business model,” Jha said.

The administration has been thinking of ways to commercialize some parts of the Covid-19 response, to get out of the business of buying vaccines and therapeutics, ultimately passing the costs on to consumers and insurers. But Jha says the process must be guided by “the needs on the ground and the realities of the virus.”

He says current realities require the government to continue to incentivize the production of new therapies, and he hopes the Biden administration will try again to ask Congress to approve more funding to do that.

“And the truth is that if we want monoclonals to protect high-risk people, which we do, then at this point, given the speed of viral evolution, the US government has to be a major player in that role,” Jha said. “The market cannot take care of it alone.”

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