(CNN) The emergence of the newly identified Omicron coronavirus variant feels like a pandemic gut check.
Scientists have long known that the world would see emerging coronavirus variants. Viruses mutate constantly.
But when South Africa's health minister announced Thursday the discovery of the B.1.1.529 variant, which appears to be spreading rapidly in parts of the country, it was the strongest reminder yet that the pandemic is not over.
In the hours following that Thursday announcement, several nations -- including the United States and the United Kingdom -- banned travel from South Africa and surrounding African countries.
The new travel restrictions announced by President Joe Biden on Friday will buy the US federal government more time to investigate the new Omicron variant that has emerged in South Africa, officials say. But not much.
Inside the government, it is seen as inevitable that the new variant will appear in the US at some point, but the new restrictions should give federal health agencies and their global counterparts more time to learn about the variant, including the severity of the disease it causes. Officials do not believe, based on current surveillance, that the variant is in the US yet.
Officials acted quickly to implement new restrictions. While the emergence of the variant had been flagged in the last several weeks, it was only in recent days that they learned how serious it was.
US officials are expected to speak to scientists in South Africa again potentially on Sunday.
The World Health Organization quickly convened a group of advisers and designated the B.1.1.529 strain a "variant of concern," giving it the Greek name Omicron. WHO also called on countries to enhance their surveillance and sequencing efforts to better understand coronavirus variants.
Vaccine makers were fast to identify the variant as a concern. Moderna said the Omicron variant represents a 'significant potential risk' to its Covid-19 vaccine.
"The recently described Omicron variant includes mutations seen in the Delta variant that are believed to increase transmissibility and mutations seen in the Beta and Delta variants that are believed to promote immune escape. The combination of mutations represents a significant potential risk to accelerate the waning of natural and vaccine-induced immunity," Moderna said Friday in a news release.
Omicron was also quick to make an economic hit. The new Covid variant sent oil plummeting 13% on Friday as investors feared new government restrictions and slower economic growth. US crude finished the day at a two-month low of $68.15 a barrel, down 13.1% from Wednesday's close. It was the worst day for oil since April 27, 2020, when Covid was spreading rapidly in the United States.
Now, as scientists work quickly to learn more about the variant, global health officials are urging people to wear masks, avoid crowded places and get vaccinated if they haven't already. Omicron is another example of how Covid-19 is here to stay.
"We understand that people are concerned. The good thing is that we have monitoring systems around the world to detect these variants very quickly. This variant was detected a few weeks ago, and already scientists are sharing research with us, information with us, so that we can take action," Maria Van Kerkhove, WHO's technical lead for Covid-19, said in a video statement Friday.
"What's really important as an individual is to lower your exposure," Van Kerkhove said. "These proven public health measures have never been more important: distancing, wearing of a mask, making sure that it's over your nose and mouth with clean hands, making sure you avoid crowded spaces, be in rooms where there's good ventilation, and when it's your turn, get vaccinated."
And as the world learns more about the Omicron variant, current guidance on mitigation measures -- such as wearing masks -- could change.
Even as the pandemic nears its end and the coronavirus becomes endemic -- meaning, it could have a constant presence but not affect an alarmingly large number of people -- it's still likely that new variants will continue to emerge.
"New variants are going to continually be generated by this virus, most of which will be inconsequential. It will remain an important task, however, to characterize and track new variants to determine their significance," Dr. Amesh Adalja, senior scholar at the Johns Hopkins University Center for Health Security, wrote in an email to CNN on Friday.
"There will never be a time when there is a zero COVID threat as the virus transitions to endemicity," Adalja wrote. "Once the virus is tamed — by losing the ability to threaten hospital capacity through high levels of population immunity and treatments — I think public health recommendations will be more relaxed, though some people may voluntarily choose to continue to use them in high risk contexts."
As we look to what the future might hold, Covid-19 vaccine makers have said that they are prepared to update their coronavirus shots to target newly emerging variants.
Scientists at BioNTech have already started investigating the impact the Omicron variant has on its vaccine developed with Pfizer, with data expected within the next couple of weeks.
"We understand the concern of experts and have immediately initiated investigations on variant B.1.1.529," BioNTech said in a statement Friday. "We expect more data from the laboratory tests in two weeks at the latest."
Moderna announced in a statement Friday that it is "working rapidly" to test the ability of its current vaccine dose against the Omicron variant and data is expected in the coming weeks.
If the current vaccine and booster shot are insufficient against the variant, one possible solution is boosting people with a larger dose, which Moderna said it is testing.
The company is also evaluating two multi-valent booster candidates to see if they provide superior protection against Omicron. Both candidates include some of the viral mutations present in the new variant.
Moderna is also evaluating an Omicron-specific booster candidate.
"Since early 2021, Moderna has advanced a comprehensive strategy to anticipate new variants of concern," the company statement said, adding that "this strategy includes three levels of response" should the currently authorized booster dose of its vaccine is insufficient to boost waning immunity against the Omicron variant.
In response to the emergence of the Omicron variant, Johnson & Johnson said in a company statement Friday: "We are closely monitoring newly emerging COVID-19 virus strains with variations in the SARS-CoV-2 spike protein and are already testing the effectiveness of our vaccine against the new and rapidly spreading variant first detected in southern Africa."
Vaccine maker AstraZeneca is looking to understand the impact the Omicron variant has on its coronavirus vaccine, and it is also testing its antibody combination therapy against the new variant, a spokesperson for the company said on Friday.
The spokesperson said that the platform used in the vaccine enables the company to respond quickly to new variants.
"AstraZeneca is also already conducting research in locations where the variant has been identified, namely in Botswana and Eswatini, that will enable us to collect real world data of Vaxzevria against this new virus variant," they said.
The company's antibody treatment, AZD7442, is also being tested against the variant, and AstraZeneca says it is "hopeful AZD7442 will retain efficacy since it comprises two potent antibodies with different and complementary activities against the virus."