For every Greek-lettered incarnation of the coronavirus that alters the course of the pandemic, like the Delta variant, there is another that falls into epidemiological obscurity, and countless more that prove too insignificant to name.
But scientists and world leaders have reacted more swiftly to the latest variant, Omicron, than to any other: Two days after South Africa reported it last week, the World Health Organization had labeled Omicron a “variant of concern,” the most serious category the agency uses for such tracking, and on Monday declared that it posed a “very high” risk to public health. A growing number of countries, including the United States, have barred foreign travelers from southern Africa, and a few have barred them from anywhere.
Why is the Omicron variant raising such alarm, and what’s the best way for governments and the public to respond? Here’s what people are saying.
What we know, and what we don’t, about Omicron
As Kai Kupferschmidt reports for Science, the Omicron variant was discovered as researchers in South Africa were trying to determine the cause of a recent surge in infections there. A lab noticed that in many samples, routine P.C.R. tests were failing to detect a gene that encodes the spike protein that the coronavirus uses to bind to human cells. The target gene, it turned out, was so heavily mutated that the tests were missing it.
This phenomenon also occurred with the Alpha variant, but the Omicron variant has far more mutations than any of its predecessors — about 50 not seen in combination before, including more than 30 mutations on the spike protein.
“This variant did surprise us: It has a big jump in evolution, many more mutations than we expected, especially after a very severe third wave of Delta,” said Tulio de Oliveira, director of the KwaZulu-Natal Research and Innovation Sequencing Platform in South Africa.
Many scientists have speculated that this extensively mutated variant might have emerged in an immunocompromised host, perhaps someone with untreated H.I.V. “Instead of getting cleared away in a matter of days,” The Times’s Carl Zimmer writes, “the virus may have lingered in that person for months, spending the time gaining the ability to evade antibodies.”
But just how troubling the Omicron variant is remains unclear. While mutations can work together to make a virus more dangerous, they can also make it less so. Dr. Ashish Jha, the dean of the Brown University School of Public Health, writes in The Times that there are three key questions about the variant that scientists still need to answer:
Does Omicron cause more severe disease? As of yet, there is no evidence that it does. Some scientists have even suggested the opposite: Barry Schoub, a South African virologist who advises the government there, said that Omicron cases have tended to be “mild to moderate.” But then again, most cases of all other variants are mild to moderate. “Let me stress it is early days,” Schoub added.
Is it more transmissible? On this front, Jha says the preliminary data from South Africa is not encouraging: It suggests that the Omicron variant may spread even more easily than Delta. “If we were looking out for mutations that do affect transmissibility, it’s got all of them,” Aris Katzourakis, an evolutionary biologist at the University of Oxford, told Science. But, Katzourakis said, it’s hard to know how infectious a virus is from mutations alone.
Can it evade immunity? Higher transmissibility than Delta is one potential explanation for Omicron’s rapid spread in South Africa. But another explanation — and not a mutually exclusive one — is that it’s better than Delta at sidestepping some antibodies.
This is a real concern, Jha says. But he adds that “it is extremely unlikely that Omicron will render the Covid-19 vaccines completely ineffective.” While spike protein mutations can enable a variant to better evade antibodies, including monoclonal antibody treatments, they do not blunt the broader immune-cell response that targets infected cells and staves off severe disease, Zimmer explains.
What’s next: Scientists in South Africa began testing coronavirus vaccines against the new variant within hours of detection, and dozens of teams have followed suit. They expect to have a clearer picture of its epidemiological risks in two to three weeks.
How should governments respond?
As Alexandra Phelan, a professor of global health policy at Georgetown University, told The Times, the pandemic forced experts to re-examine their skepticism of border closures as an effective public-health measure. “We gained a bit of nuance, and realized that travel restrictions have a potential role to play in slowing the spread of a new respiratory disease, even though it doesn’t stop it,” she said.
[“What the data say about border closures and Covid spread”]
Yet many experts say that some of the current border closures will not be effective on their own. The ban that President Biden announced last week, for example, applies only to travelers from several southern African countries, even though cases have also been detected in Canada, Belgium, Britain and Australia. Scientists do not even know where the variant originated, and some have said it may well already be in the United States.
What’s more, the ban exempts American citizens and permanent residents, which is perhaps politically necessary but epidemiologically nonsensical if not at least paired with strict quarantining requirements and genomic surveillance.
“While these measures will certainly be disruptive to international travel, they will do little to prevent the importation of the virus,” writes Karen Grépin, an associate professor at the School of Public Health at the University of Hong Kong who has published research on pandemic border policy.
Many public health experts also worry that the ban on travel from southern African countries will prove counterproductive in the long term. After all, the world knows about Omicron in the first place only because South Africa’s sophisticated genomic surveillance program detected it and because the government made the altruistic choice to report it. In return for that transparency, the country is effectively being economically penalized.
If world leaders do feel a need to issue travel bans, The Times’s Peter Coy argues, they should be prepared to offset their cost: “The prize should be big enough to fully compensate South Africa for the harm it is suffering for its good work. Better yet, the prize should overcompensate South Africa so that it and other countries will have a strong financial incentive to redouble their efforts to find and report future variants.”
In the coming weeks, there is much more the United States could be doing to prepare for Omicron, the Times columnist Zeynep Tufekci argues.
To start with, she says, the country needs a stricter testing regime involving multiple tests over time and quarantine requirements for all travelers, as well as more widespread testing and tracing to cut off the spread of the variant.
Vaccine makers should start producing Omicron-specific shots, and the Food and Drug Administration should prepare to quickly approve them.
New antiviral drugs that may cut down death rates and hospitalizations in high-risk patients by as much as 90 percent are not affected by variant mutations, but they have yet to be authorized and are likely to cost upward of $500 per treatment. “Such drugs need to go wherever there are outbreaks, not be hoarded by wealthy countries with early contracts,” she writes.
How worried should you be?
For now, Omicron may be a source of uncomfortable uncertainty, but it’s not a reason to panic. “Maybe it will prove to be worse than the very early signs suggest and cause more severe illness than Delta,” The Times’s David Leonhardt writes. “But assuming the worst about each worrisome new variant is not a science-based, rational response. And alarmism has its own costs, especially to mental health.”
In the meantime, experts say getting a booster shot can help hedge against whatever risk Omicron might pose. “If we have a variant that is antigenically distant and isn’t neutralized at a certain level of antibody, there is something we can do: We can boost the overall antibody levels, because sometimes quantity can compensate for the lack of match,” said Wendy Barclay, a virologist at Imperial College London. “I would strongly urge people to take the opportunity to give their immune systems the best quantitative chance that they have by getting booster doses and the full course of vaccination.”
The bottom line: “Do not take Omicron lightly, but don’t abandon hope either,” Katelyn Jetelina, an epidemiologist, writes. “Our immune systems are incredible. None of this changes what you can to do right now: Ventilate spaces. Use masks. Test if you have symptoms. Isolate if positive. Get vaccinated. Get boosted.”
The New York Times
