What four experts are saying about Omicron, the new COVID variant

Crowds of people walk past a sign encouraging passerby to get the COVID-19 vaccine in downtown Boston this summer.Erin Clark/Globe Staff

Within 72 hours of Omicron’s christening, governments across the globe swiftly shut down air travel from a handful of countries in southern Africa. Doomsaying headlines labeled the highly mutated coronavirus variant “Frankenstein.” Stock markets shivered. COVID had roared back into public consciousness after a fall of relative normalcy.

Dread swept the globe despite the fact that scientists knew relatively little about the new variant beyond its genetic composition. For now, their attitude toward Omicron remains one of vigilant curiosity, not panic.

“Did the scientific discovery or the policy reaction create the panic? It’s hard to know, because they happened in such rapid succession,” said Rachael Piltch-Loeb, a fellow at the Harvard T.H. Chan School of Public Health, focusing on ways to improve public health systems.

Early detection is double-edged sword. Scientists are able to find and flag potentially worrisome variants early enough to give vaccine manufacturers, government officials, and epidemiologists helpful lead time to study their implications and prepare accordingly. But they are often detected long before there are substantial data to contextualize a variant, creating a limbo period where there is mounting anxiety paired with little certainty.

Virologists told the Globe that they need to be able to answer three principal questions before making any hard declarations about Omicron.

First, the world needs more data from multiple sources on how rapidly the variant is spreading among diverse groups, and whether it will outcompete the Delta variant. Current data focus on a cohort of mostly younger individuals from Gauteng Province, home to South Africa’s biggest city of Johannesburg and over a dozen universities.

“I need to see the epidemiological studies that show how Omicron competes with Delta,” said Paul Duprex, a molecular virologist at the helm of University of Pittsburgh’s Center for Vaccine Research. “Does it replace Delta, or does it die out like the other variants that Delta superseded? The word I like to think of is ‘fitness.’ ”

John Moore, a virologist at Weill Cornell Medicine in New York City, views the next few weeks as a battle royale between Delta and Omicron.

“We’re in this perverse situation where you’re rooting for the devil you know over the devil you don’t. If Delta continues to dominate, it’s the devil we know,” Moore said. “And we know that the vaccines can continue to substantially protect against it. We know close to nothing about Omicron.”

Second, it remains unknown how effective current vaccines and immunity will be against Omicron. When South African researchers analyzed genome-sequencing data from Botswana, the variant stood out because it contains more than 30 changes in the spike protein, which the virus uses to infiltrate human cells.

The mRNA vaccines from Pfizer and Moderna instruct the cell’s machinery to produce a similar spike protein — a harmless replica — that prompts the body to create antibodies to fight off what it sees as an infection, thus preparing it for the real thing. But the more the virus mutates, the more potential it has to evade those antibodies.

“How resistant is it to the antibodies created by natural infection? And then by one, two, three doses of a vaccine? How about a combination of infection and vaccine?” asked Kevin McCarthy, a microbiologist at the University of Pittsburgh studying the evolution of viruses and their hosts.

Lastly, it remains unknown if Omicron causes more mild or severe cases of COVID-19 than previous iterations of the virus. Anecdotal reports suggest that the original burst in cases occurred among university students in Pretoria who were celebrating the end of the academic year, a factor that could further distort early theories about the degree of disease Omicron causes. (The South African school year runs from January to December.)

“You’re seeing reports in South Africa that Omicron is causing mild infections,” said Moore. “It’s early days, but if the cases are mostly in college kids then of course the cases are mild because college kids tend to have mild infections. But that doesn’t tell you anything about what Omicron would do to a nursing home population.”

All three manufacturers with US-approved vaccines — Johnson & Johnson, Pfizer-BioNTech, and Moderna — said that they will test how well their vaccines protect against the new variant, but it could be a few weeks before they have those data in hand. In the meantime, the drug makers are accelerating the development of Omicron-specific vaccine candidates. It’s unclear whether modified vaccines are needed, but officials for both Pfizer and Moderna have said they could make Omicron-specific versions of their mRNA vaccines by early next year. Johnson & Johnson said it is also pursuing a potential vaccine targeting Omicron. That’s a much swifter timeline than the effort to get the first COVID-19 vaccines authorized last year.

“The beauty of the mRNA vaccines is that they can pretty efficiently adjust production to target changes in the spike protein,” said Duprex. But he also cautioned that it is not hard to imagine a scenario in the near future where a Massachusetts resident is rolling up his sleeve for an Omicron-specific booster, all while a person in rural Botswana remains without access to even a first dose.

Virologists emphasized that the biggest takeaway from Omicron’s development so far is that global health is personal health. The hoarding of limited COVID-19 vaccines by rich countries — where citizens can readily walk into pharmacies for their third shot — creates vaccine deserts in poorer nations. Africa is the least vaccinated continent in the world with just 10 percent of the population vaccinated, compared with 64 percent in North America and 62 percent in Europe. And those doses are concentrated in wealthy countries like Morocco and South Africa. Such vaccine inequity, experts said, threatens the entire globe by allowing the disease to spread among unvaccinated populations.

“This pandemic started as a global crisis, and it will be resolved as a global phenomenon as well,” explained Piltch-Loeb. “The reality is that the more cases of COVID, the more opportunity for the virus to mutate.”