Washington, Jan. 15 (US): Get ready to learn more Greek letters. Scientists warn that the advance of the omicron whirlwind practically guarantees that it will not be the last version of the coronavirus that worries the world.
Each infection presents an opportunity for the virus to mutate, and Omicron has an advantage over its predecessors: it spreads faster despite appearing on a planet with a stronger mixture of immunity than previous vaccines and diseases.
This means more people with whom the virus can develop. Experts don’t know what the next variants will look like or what they might shape the epidemic, but they say there is no guarantee that omicron sequences will cause milder disease or that current vaccines will work against them.
a
They urge now, while today’s shots are still working. “The faster the omicron spreads, the higher the chances of mutations, which could lead to more variants,” said Leonardo Martinez, an infectious disease epidemiologist at Boston University.
Since its appearance in mid-November, Omicron has raced across the globe like fire through dry grass. Research shows that the variant is at least twice as infectious as Delta and at least four times as infectious as the original version of the virus.
Omicron is more likely to reinfect individuals who previously contracted COVID-19 and cause “penetrating infections” to vaccinated people while also attacking the unvaccinated. The World Health Organization reported 15 million new cases of COVID-19 for the week of January 3-9, an increase of 55% over the previous week.
Besides keeping relatively healthy people away from work and school, the ease with which the variant spreads increases the odds of the virus becoming infected and remaining inside people with weakened immune systems — giving it more time to develop strong mutations.
“Long and persistent infections are likely to be a breeding ground for new variants,” said Dr. Stuart Campbell Ray, an infectious disease expert at Johns Hopkins University. “Only when you have a very widespread infection will you provide the opportunity for that to happen.”
Since Omicron appears to cause less serious disease than Delta, its behavior has raised hope that it could be the start of a trend that will eventually make the virus milder like the common cold.
Experts say it’s a possibility, since viruses don’t spread well if they kill their hosts too quickly. But viruses don’t always get less deadly over time.
Ray explained, for example, that the alternative could achieve its main goal – replication – if infected people initially developed mild symptoms, spread the virus through interactions with others, and later became very ill.
People wondered if the virus would develop into moderation. But there is no particular reason to do so, he said. “I don’t think we can be confident that the virus will become less deadly over time.”
Gradual improvement in immune evasion helps the virus survive in the long term. When SARS-CoV-2 first hit, 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 avenues for evolution.
Animals can cuddle and unleash new variables. Domestic dogs and cats, deer and farm-raised mink are just a few of the animals susceptible to the virus, which can mutate inside and jump back into humans.
Another possible route: With both omicron and delta circulating, people might develop a double infection that could spawn what Ray calls “Franken variants,” hybrids that have characteristics of both types.
When new variants evolve, the scientists said it’s still very difficult to tell which genetic traits might take off.
For example, the omicron contains many more mutations than previous variants, about 30 in the spike protein that allows it to bind to human cells.
But the so-called IHU variant identified in France that is being monitored by the World Health Organization has 46 mutations and does not appear to have spread much at all.
To limit the emergence of variants, scientists are stressing the continuation of public health measures such as masking and vaccination.
While Omicron is better able to evade immunity than Delta, experts said, vaccines still provide protection, and booster vaccines significantly reduce critical illness, hospitalizations and deaths.
Ray likened vaccines to human shields that greatly hinder the spread of the virus, even if they do not stop it completely. For a virus that spreads exponentially, he said, “Anything that limits its transmission can have a huge impact.”
Also, when vaccinated people get sick, Ray said their illness is usually milder and goes away more quickly, leaving less time to produce dangerous variants.
Experts say the virus will not become a pandemic like the flu as long as global vaccination rates are very low. During a recent press conference, WHO Director-General Tedros Adhanom Ghebreyesus said protecting people from future variables — including those that may be completely resistant to current shots — depends on ending global vaccine inequalities.
Tedros said he would like to see 70% of people in every country receive the vaccination by the middle of the year. Currently, there are dozens of countries where less than a quarter of the population is fully vaccinated, according to Johns Hopkins University statistics.
And in the United States, many people continue to resist available vaccines. Dr Prabhat Jha of the Center for Global Health Research at St Michael’s Hospital in Toronto said. “It was such a fiasco of global leadership that we just couldn’t do it.”
Meanwhile, Louis Mansky, director of the Institute for Molecular Virology at the University of Minnesota, said new variants are inevitable.
With so many unvaccinated people, he said, “the virus is still kind of in control of what’s going on.”
insult