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Expect more worrying variants after omicron, scientists say

Get ready to learn more Greek letters. Scientists warn that the meteoric advance of omicron all but guarantees it won’t be the last version of the coronavirus to worry the world about.

Each infection offers a chance for the virus to mutate, and omicron has an advantage over its predecessors: it spreads much faster despite emerging on a planet with a stronger mosaic of immunity to vaccines and earlier diseases.

This means more people in whom the virus can evolve further. Experts don’t know what the next variants will look like or how they might shape the pandemic, but they say there’s no guarantee that omicron sequelae will cause milder disease or that existing vaccines will work against them. .

They urge broader vaccination now, when today’s vaccines still work.

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“The faster the omicron spreads, the more opportunity there is for mutation, potentially leading to more variants,” said Leonardo Martinez, an infectious disease epidemiologist at Boston University.

Since its appearance in mid-November, omicron has raced across the world like fire through dry grass. Research shows the variant is at least twice as contagious as delta and at least four times as contagious as the original version of the virus.

Omicron is more likely than delta to re-infect people who previously had COVID-19 and cause “breakthrough infections” in vaccinated people while also attacking unvaccinated people. The World Health Organization reported a record 15 million new cases of COVID-19 for the week of January 3-9, a 55% increase from the previous week.

In addition to keeping relatively healthy people out of work and school, the ease with which the variant spreads increases the chances of the virus infecting and persisting inside people with weakened immune systems. which gives him more time to develop powerful mutations.

“It is the longer and more persistent infections that appear to be the most likely breeding grounds for new variants,” said Johns Hopkins University infectious disease expert Dr. Stuart Campbell Ray. “It’s only when you have a very widespread infection that you’re going to give the opportunity for that to happen.”

Because the omicron appears to cause less severe disease than the delta, its behavior has raised hopes that it could be the start of a trend that will eventually make the virus milder like a cold.

That’s a possibility, experts say, since viruses don’t spread well if they kill their hosts very quickly. But viruses don’t always become less deadly over time.

A variant could also achieve its primary purpose – replication – if infected people initially develop mild symptoms, spread the virus by interacting with others, and then later become very ill, Ray explained as an example.

“People wondered if the virus would evolve into softness. But there is no particular reason for him to do so,” he said. “I don’t think we can be sure that the virus will become less lethal over time.”

Gradually improving to escape immunity helps a virus to survive long term. When SARS-CoV-2 first struck, no one was immune. But infections and vaccines have given at least some immunity to much of the world, so the virus must adapt.

There are many possible paths of evolution. Animals could potentially incubate and release new variants. Pet dogs and cats, deer and farmed mink are just some of the animals vulnerable to the virus, which can potentially mutate within them and revert back to humans.

Another potential route: With omicron and delta circulating, people can contract a dual infection that could spawn what Ray calls “Franken variants,” hybrids with characteristics of both types.

When new variants develop, the scientists said it is still very difficult to know from genetic characteristics which ones might take off. For example, omicron has many more mutations than previous variants, about 30 in the spike protein that allows it to attach to human cells. But the so-called IHU variant identified in France and monitored by the WHO has 46 mutations and does not seem to have spread much.

To curb the emergence of variants, scientists insist on the continuation of public health measures such as mask wearing and vaccination. Although omicron is better at evading immunity than delta, experts say vaccines still provide protection and booster shots significantly reduce serious illness, hospitalizations and deaths.

Anne Thomas, a 64-year-old computer analyst in Westerly, Rhode Island, said she was fully vaccinated and beefed up and also trying to stay safe by mostly staying home as her condition has one of the highest COVID-19 case rates in the United States.

“I have no doubt that these viruses are going to keep mutating and we’re going to deal with that for a very long time,” she said.

Ray compared vaccines to an armor for humanity that significantly hinders viral spread even if it doesn’t stop it completely. For a virus that is spreading exponentially, he said, “anything that slows transmission can have a big effect.” Also, when vaccinated people get sick, Ray said their illness is usually milder and goes away faster, leaving less time for dangerous variants to develop.

Experts say the virus won’t become endemic like the flu as long as global vaccination rates are this low. At a recent press conference, WHO Director-General Tedros Adhanom Ghebreyesus said protecting people from future variants – including those that may be fully resistant to today’s vaccines – depends of ending global vaccine inequality.

Tedros said he would like to see 70% of people in every country vaccinated by the middle of the year. Currently, there are dozens of countries where less than a quarter of the population is fully immunized, according to statistics from Johns Hopkins University. And in the United States, many people continue to resist available vaccines.

“These huge unvaccinated swaths in the United States, Africa, Asia, Latin America and elsewhere are essentially variant factories,” said Dr. Prabhat Jha of the Center for Global Health Research at St. Michael’s Hospital. of Toronto. “It was a colossal failure in global leadership that we weren’t able to do that.”

In the meantime, new variants are inevitable, said Louis Mansky, director of the University of Minnesota’s Institute of Molecular Virology.

With so many people unvaccinated, he said, “the virus is still kind of in control of what’s going on.”


The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute Department of Science Education. The AP is solely responsible for all content.


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