When both Omicron and Delta circulate, people can get dual infections that can give birth to “Franken variants”, hybrids with characteristics of both types
Get ready to learn more Greek letters. Researchers warn that Omricron’s whirlwind advances virtually ensure it does not become the latest version of the coronavirus to worry the world.
Any infection gives a chance that the virus can mutate, and Omicron has an advantage over its predecessors: It spreads much faster despite appearing on a planet with a stronger patchwork of immunity to vaccines and previous disease.
This means more people in whom the virus can develop further. Experts do not know what the next variants will look like or how they may shape the pandemic, but they say there is no guarantee that the successors of Omicron will cause milder disease or that existing vaccines will work against them.
That’s why they’re calling for broader vaccination now, while today’s shots are still working.
“The faster Omicron spreads, the more possibilities there are for mutation, which could potentially lead to more variants,” said Leonardo Martinez, an infectious disease epidemiologist at Boston University.
Since it appeared in mid-November, Omicron has been running across the globe like fire through dry grass. Research shows that 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 have previously had Covid-19 and to cause “breakthrough infections” in vaccinated people while also attacking the unvaccinated. The World Health Organization reported a record 15 million new Covid-19 cases in the week 3-9. January, an increase of 55 percent over the week before.
Along with keeping relatively healthy people out of work and school, the ease with which the variant spreads increases the chances that the virus will infect and linger in people with weakened immune systems – giving it more time to develop potent mutations.
“It’s the longer, persistent infections that seem to be the most likely breeding ground for new varieties,” said Dr. Stuart Campbell Ray, an infectious disease expert at Johns Hopkins University. “It’s only when you have a very widespread infection that you will allow that to happen.”
Because Omicron appears to cause less serious illness than Delta, its behavior has raised hopes that it could be the start of a trend that will eventually make the virus milder like a common cold.
That’s a possibility, experts say, given that viruses do not spread well if they kill their hosts very quickly. But viruses do not always become less deadly with time.
A variant could also achieve its main goal – to replicate – if infected people developed mild symptoms in the beginning, spread the virus by interacting with others and then became very ill later, Ray explained as an example.
“People have wondered if the virus will develop into mildness. But there is no particular reason for that,” he says. “I do not think we can be sure that the virus will become less deadly over time.”
Gradually getting better at avoiding immunity helps a virus survive long-term. When SARS-CoV-2 first struck, no one was immune. But infections and vaccines have given at least some immunity to large parts of the world, so the virus has to adapt.
There are many possible paths to development. Animals can potentially incubate and release new varieties. Pet dogs and cats, deer and mink bred on the farm are just a few of the animals that are vulnerable to the virus, which can potentially mutate in them and jump back to humans.
Another potential route: When both Omicron and Delta circulate, people can get dual infections that can give birth to what Ray calls “Franken variants,” hybrids with characteristics of both types.
As new varieties evolve, scientists said it is still very difficult to know from genetic traits which ones may take off. For example, Omicron has many more mutations than previous variants, about 30 in the tip protein that allow it to bind to human cells. However, the so-called IHU variant, identified in France and monitored by the WHO, has 46 mutations and does not appear to have spread much at all.
To curb the emergence of variants, researchers emphasize continuing with public health measures such as masking and being vaccinated. Although omicron is better able to evade immunity than delta, experts said, vaccines still offer protection, and booster shots greatly reduce serious illness, hospitalizations and deaths.
Anne Thomas, a 64-year-old IT analyst in Westerly, Rhode Island, said she is fully vaccinated and boosted and is also trying to stay safe by mostly staying home while her state has one of the highest Covid -19 cases in the United States.
“I have no doubt at all that these viruses will continue to mutate and we are going to deal with this for a very long time,” she said.
Ray compared vaccines to armor for humanity, which greatly prevents viral spread, though it does not completely stop it. For a virus that spreads exponentially, he said, “anything that slows transmission can have a big effect.” Also, when vaccinated people get sick, Ray said their disease is usually milder and disappears faster, giving less time to create dangerous varieties.
Experts say the virus will not become endemic like the flu as long as global vaccination rates are so low. At a recent press conference, WHO Director-General Tedros Adhanom Ghebreyesus said that protecting humans from future variants – including those that may be fully resistant to today’s shots – depends on bringing global vaccine inequality to life.
Tedros said he would like 70 percent of the population in all countries to be vaccinated by mid-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.
“These huge unvaccinated shards in the United States, Africa, Asia, Latin America and elsewhere are fundamentally different factories,” said Dr. Prabhat Jha from the Center for Global Health Research at St. Michael’s Hospital in Toronto. “It has been a colossal failure in global management that we have not been able to do this.”
Meanwhile, new variants are inevitable, said Louis Mansky, director of the Institute of Molecular Virology at the University of Minnesota.
With so many unvaccinated people, he said, “the virus still has some control over what goes on.”