- Omicron has been labeled a variant of concern due to its high transmissibility and number of mutations.
- Experts say that low vaccination rates can lead to increased spread of the virus and further mutations.
- Getting the whole world vaccinated and boosted is imperative to help stop the spread of COVID-19 and prevent future worrisome variants from emerging.
As cases of the Omicron continue to crop up all over the world, researchers are racing to better understand the variant and its potential impact on the global COVID-19 pandemic.
The new coronavirus variant first identified in South Africa has been named a “variant of concern” by the World Health Organization (WHO). It has prompted a number of countries, including the United States, to roll out new travel restrictions in an attempt to thwart its spread.
However, there’s still a lot to learn about the Omicron variant. Public health officials say that it’s too soon to say how widespread it will become and to determine its true impact on the course of the pandemic.
Healthline asked two experts who specialize in virology and infectious diseases to explain how variants like Omicron develop, why Omicron is considered a “variant of concern,” and how low vaccination rates may lead to additional coronavirus variants.
All viruses, including the novel coronavirus, evolve over time.
“Anytime somebody gets infected with a virus, the virus enters their body and enters their cells and starts making copies of itself,” explains Dr. Marybeth Sexton, assistant professor of infectious diseases at Emory University School of Medicine. “And every time the virus copies itself, there’s a chance for it to make an error.”
Sexton compares this to typing out a transcript — you’re bound to make some typos.
“It’s the same thing with a virus,” she says. “When it copies itself, it makes mistakes. Most of those mistakes don’t matter, but occasionally, you’ll get a mistake that actually makes the virus more contagious, or more severe, or causes other problems, like a treatment or a vaccine doesn’t work as well. And that’s when we start to get worried.”
Since SARS-CoV-2 was first identified in 2019, thousands of variants have arisen. The vast majority of these mutations have had little to no impact.
But depending where the mutations occur on the virus’s genetic material, the virus’s properties may be affected, including transmission and severity of disease.
The WHO currently categorizes variants into three main categories: variants of interest, variants of concern, and variants of high consequence.
“These essentially tell us how worried we should be and how quickly we need to act to protect ourselves and our communities,” Sexton says.
According to the WHO, a variant of interest (VOI) has genetic changes that are predicted or known to affect transmissibility, disease severity, immune escape (such as evasion of vaccines), or a change in the ability to diagnose or treat it.
A VOI also typically causes an increased proportion of disease in an area or a cluster outbreak.
“But usually with a variant of interest, we’re not seeing huge, widespread cases throughout the U.S. or throughout another country,” Sexton explains.
A variant of concern (VOC) meets all the criteria for a VOI, but there’s evidence that it either spreads more easily, causes more severe disease, or doesn’t respond as well to current tests, vaccines, or treatments.
“With a variant of concern, not only do we need to watch it, we also need to act on it fairly quickly to stop it from going to the next category, which is variant of high consequence,” explains Gary Whittaker, PhD, professor of virology at Cornell University.
We haven’t yet seen a variant of high consequence, but this category would mean that the virus evades vaccines, diagnostic tests, or treatments. There would also be a lot more severe disease and hospitalizations.
“Basically with a variant of high consequence, we would have a big problem,” Sexton says.
While much still needs to be learned about Omicron, several factors have made it a variant of concern.
“One is that there is some evidence that it may be more transmissible,” Sexton says, “and that’s based on the fact that we’re seeing a rapid increase in the number of cases of COVID in South Africa at the same time that the proportion of cases that they’re identifying that are Omicron is going up.”
The number of mutations Omicron has is also concerning.
“It has a lot of changes, or a lot of those typos or errors, compared to the original virus,” Sexton explains. “And to see that, that starts to worry people about how well our vaccines and treatments are going to work. But we still need a lot more data.”
Low vaccination rates can lead to additional coronavirus variants in two ways: One is related to the population as a whole, and another relates to the individual.
Because there’s a chance of errors every time a virus copies itself, viruses can mutate every time they replicate.
“They have to be spreading and infecting new people in order to replicate and make those mistakes,” Sexton explained. “And so if you have a fully vaccinated population, then the virus just doesn’t spread that well. And so it doesn’t get opportunities to make these errors.
“But if you’ve got a lot of unvaccinated people, you’re going to have a lot of spread,” she continued. “And when you have a lot of spread, the virus is copying itself. And when it’s copying itself, you get mutations.”
At an individual level, when a person contracts SARS-CoV-2, being vaccinated lowers the chance that the virus will mutate.
“What we’re starting to learn is that even if you get a breakthrough infection, meaning a person has been vaccinated but still gets COVID, those people don’t seem to be contagious for as long,” Sexton says.
“That’s because even if the virus is able to get in there a little bit, eventually, your immune system response that was developed by the vaccine kicks in and clears it out faster.”
In an unvaccinated person, it remains in the body for much longer, giving it more time to copy itself.
“So an unvaccinated person who’s infected is a better incubator to make a variant because the virus copies itself more inside of them, and then an unvaccinated population allows it to spread,” Sexton says.
For these reasons, it’s important that everyone get vaccinated against COVID-19 and get their booster shot when they’re eligible, Whittaker says.
Other precautions we’ve come to rely on, such as mask-wearing, handwashing, and social distancing can also have a big impact.
“Obviously, if you’re not feeling well, don’t go out and mingle with other people,” Whittaker said. “And if you are feeling well, if you can get access to regular rapid testing, that’s certainly a big part of the way to deal with this, as well.”
It’s also imperative that vaccine inequality across the globe, which has caused delayed or slow rollout of vaccinations in low and middle income countries, is addressed.
According to the Global Dashboard for Vaccine Equity, which was established by the United Nations, WHO, and Oxford University, just 8 percent of people in low income countries have received at least one dose of a COVID-19 vaccine as of Dec. 8.
That’s compared to 65 percent in high income countries, which started vaccinating their populations an average of 2 months before low income countries. Access to vaccines in low income countries remains alarmingly low.
“This is the definition of we’re all in this together,” Sexton says. “We’re going to see the virus spread rapidly in places that haven’t vaccinated their population, and so this is really a setup to have variants continue to emerge from under-vaccinated, disadvantaged countries over and over again until we fix this and really get the whole world access to the vaccine.”