(NEXSTAR) – With public health officials around the world bracing for the spread of omicron, will a booster shot tailored to defend against the mutated COVID variant become necessary?

The variant, discovered by South African researchers last week, prompted the World Health Organization to warn Monday that the global risk is “very high” and that extensive transmission could result in “severe consequences.”

As confirmed cases surfaced in several countries, the Centers for Disease Control and Prevention expanded its guidance around COVID-19 vaccine boosters, recommending them for all adults.

On Monday, President Biden urged Americans to get fully vaccinated, adding in a tweet, “In the event — hopefully unlikely — that updated vaccinations or boosters are needed to respond to omicron, we will accelerate their development and deployment with every available tool.”

Moderna’s Chief Medical Officer Paul Burton said over the weekend that, if necessary, the drug company could reformulate the vaccine to target omicron by early 2022.

“We should know about the ability of the current vaccine to provide protection in the next couple of weeks, but the remarkable thing about the mRNA vaccines, Moderna platform is that we can move very fast,” Burton said during an appearance on BBC’s “Andrew Marr Show.”

Despite countries scrambling to restrict travel and prepare for the worst case scenario, there is still much to be learned about how transmissible, vaccine-evasive and deadly the new variant will actually prove to be.

For that reason – and the lack of evidence that vaccines fail to protect against hospitalization and death from omicron – a targeted booster shot isn’t yet necessary to combat the mutated variant, according to Dr. Peter Chin-Hong, an infectious disease specialist at the University of California, San Francisco.

“I don’t think it will happen with omicron, but it is a good model for something that might happen in the future,” said Dr. Chin-Hong about the COVID-19 vaccine code, which can easily be updated against other threats. “We’ve seen lots of things that look scary in biology, but when it comes out on the playing field and interacts with real humans it doesn’t look quite as bad.”

While still early, initial reports out of South Africa have documented “unusual but mild” symptoms. In a FOX News report, Dr. Angelique Coetzee, who is a board member of the South African Medical Association, said she first noticed unusual symptoms on Nov. 18. 

“It presents mild disease with symptoms being sore muscles and tiredness for a day or two not feeling well,” Coetzee said. “So far, we have detected that those infected do not suffer the loss of taste or smell. They might have a slight cough.”

While omicron doesn’t yet deserve a specialty booster rollout, according to Dr. Chin-Hong, there are variant characteristics that might warrant one.

“If there’s a situation where you’re seeing boosted people come into the hospital with omicron, that would be a scary situation,” he said.

Chin-Hong said Tuesday he was “100-percent” certain that omicron was already in the United States. On Wednesday, health officials confirmed that the first documented case was detected in California.