The new COVID BA.4.6 variant promises to be the nightmare of Deja Vu.

The world has developed a lot of immunity in the nine months since Omicron's launch new coronavirus It became the parent, leading to a wave of record-breaking injuries.

This immunity from previous vaccinations and infections helps reduce hospitalizations and deaths even as Omicron's offspring, a series of subvariants, have become dominant, one by one.

The virus is now trying to find a way to get past our antibodies. A new subsidiary, BA.4.6, is starting to surpass its predecessor, BA.5. Its benefits include a specific mutation in the spike protein, which is part of the virus that helps it attach and infect our cells.

We have already seen this R346T boom. And whenever it appears, it is related to forms of the SARS-CoV-2 pathogen with a greater ability to evade our antibodies. Invitation from high quality epidemiologists "Immune escape".

If BA.4.6 becomes dominant, it could reflect the encouraging trend we've seen in most countries in recent weeks towards fewer infections, fewer hospitalizations and fewer deaths.

It reminds us that the new coronavirus is something alive and evolving. When we adapt to it, it adapts to us. "Viruses generally evolve to become more contagious and evade our immunity," Ali Mokdad, a professor of health metrics science at the University of Washington Institute of Health, told the Daily Beast.

Don't panic just yet. "One of the things I try not to do is get too excited about every new variant that comes up," Peter Hotez, vaccine development expert at Baylor College, told the Daily Beast.

Most coronavirus variants and subvariables appear and disappear without major changes in the overall course of the epidemic. There is also A new type of vaccine In companies that can help us fight the worst forms of COVID in the long term. at the end.

However, BA.4.6 deserves a lot of attention. It is the seventh major variant for Omicron, which debuted in Africa in November. It spread rapidly, surpassing the previous major variant, the Delta. Epidemiologists have described Omicron and its sub-variants as the most infectious respiratory virus they have ever seen.

Omicron is four times more transmissible than Delta but semi-fatal. So Omicron turned out to be the worst day in history for the new COVID infections when A record of 4.1 million people I got sick on January 19th. This is a fivefold increase from the Delta's worst day in April last year.

But only 13,000 people died on Omicron's worst day cases of death February 9: Thousands fewer deaths than those killed on the Delta's deadliest day in January 2021.

It is not difficult to explain the growing gap between infections and deaths as the pandemic approaches its fourth year. Billions of people have been at least partially vaccinated. Billions of people were infected with the coronavirus and survived. The combination of natural and vaccine-induced antibodies has created a global wall of immunity that harms the worst outcomes.

But with BA.4.6, the virus is trying to get around this wall. "There is tremendous selective pressure for immune escape, especially now that the vast majority of the population has some degree of immunity, either through immunization or infection or both," Keith Jerome, a virologist, told the Daily Beast. of the University of Washington.

SARS-CoV-2 is, in essence, fighting for its survival, experimenting with mutations until it settles on the one that could give it the upper hand.

R346T is one of those mutations. It is not entirely clear how the virus caused the change. It is possible that Omicron has mixed with an older type of SARS-CoV-2 in someone who has gotten sick more than once. In other words, it is possible that BA.4.6 was a "recombinant" subvariable that captured its most useful quality from one of its predecessors.

This change in the spike protein appears to make the virus a little more difficult to identify on our antibodies. With R346T, the virus has a better chance of overcoming our immune system and causing an infection. Even if we are vaccinated. Although we have also discovered COVID and beat it in the past.

Greater immune leakage means more and more serious infections. We were lucky with Omicron as even though the variable and its dependent variables have driven successive waves of cases since November, hospitalizations and deaths have not increased proportionally.

It is still an open question to what extent BA.4.6 can be worse and to what extent it can be extended. Health agencies around the world have been monitoring the variable for months. With stable BA.5 states, BA.4.6 exceeds BA.5, but not everywhere.

BBA 4.6 hotspots include some Australian states and parts of the American Midwest. So far, BA.4.6 accounts for around four percent of new cases in the US, Canada and the UK.

BA.4.6 is set to go up with BA.5 to go down. It appears that BA.4.6 only has 10% growth advantage More than BA.5, but this advantage increases over time.

If there is any good news in the boom of BA.4.6 it is with all the worrying booms resident Omicron sub-strain, and still has many mutations in common with BA.5, BA.4, BA.2 and BA.1.

This means that the Omicron boosters Pfizer and Moderna are developing for messenger RNA vaccines, which are expected to be approved by US regulators in the coming weeks, should at least work to some degree against BA.4.6.

BA.4.6 is not the worst case. This would be a secondary variant, or a completely new variant, with a strong immune escape. A form of SARS-CoV-2 that has mutated so much that almost all the antibodies we've generated in the past three years barely recognize it.

The epidemiological community is divided on the likelihood of this variant developing. Some are confident that respiratory viruses such as the flu and the novel coronavirus tend to become milder over time as they become "endemic"; this is always present but is usually manageable.

Others fear that an almost complete immune escape is inevitable for the more intelligent viruses that fight tirelessly for survival. "This idea that each successive variant causes a less severe disease, I don't buy it," Hotez said.

"So far the virus has met with great success."

It's all a matter of genetics - the virus swaps one quality for another as it tries to spread to more and more hosts. "The trick of the virus is to find a way to escape immunity while maintaining the ability to efficiently infect new people," explained Jerome.

So far, the virus has been very successful in doing so, but the big question is whether it can keep doing it, or will it eventually run out of all possible tricks to do so, settling at a more manageable level of endemicity. There is still no way to know for sure. "

A variant or variant with near-complete immune escape could take us back to the scariest days of an early pandemic, when no one had immunity, or at all. developing immunity without surviving a very serious infection.

But BA.4.6 with the R346T mutation and the possibility of immune escape could be a preview of this worst case scenario. It could also be an argument for the pharmaceutical industry and health agencies to redouble their efforts to create universal vaccines that work against SARS-CoV-2 and all other major coronaviruses, of which there are dozens.

There are about a dozen major pan-coronavirus vaccines in development. The two main efforts are the Norwegian Coalition for Epidemic Preparedness Innovations and the US government's National Institute of Allergy and Infectious Diseases.

They spend $ 200 million and $ 43 million respectively to develop their new global routes. The tests are still months, if not years later. "We are gradually moving towards a more comprehensive coronavirus vaccine," said Hotez.

Pan-coronavirus vaccines may be slightly less effective than the best mRNA vaccines that were at their peak (against serious illness and death) by over 90 percent at the end of 2020.

But it will be effective on a large scale, keeping people alive and out of the hospital even as the virus mutates over and over to survive.