KNOXVILLE, Tenn. (WATE) — Just as the state health department commissioner predicted early last week, the omicron variant of COVID-19 has arrived in Tennessee; specifically, the Knox County Health Department said Friday that the first local case of the omicron variant has been detected.

 Health officials in Nashville also reported their first local omicron case Thursday. Here are 6 things to know about this latest coronavirus variant and why scientists are calling it the “most mutated virus” they’ve seen.

Emergence of ‘variant of concern’ out of South Africa

In late November, scientists in South Africa detected the COVID-19 variant called  B.1.1529, also known as omicron from the Greek alphabet. The World Health Organization (WHO) held an emergency meeting on Friday, Nov. 26 where it designated the new strain, which it called omicron, a “variant of concern,” or VOC, a label applied when a particular strain is especially virulent, transmissible or able to defeat public health measures.

Health authorities in European countries like the Netherlands, Belgium and Germany later said they found the new omicron variant in samples which predated those in South Africa, suggesting the variant was already spreading in Europe when South African scientist first made the discovery.

Early data suggests omicron cases more mild, but better at evading vaccines

Analysis of data from South Africa suggests that the omicron variant appears to cause less severe disease that previous version of the coronavirus and the Pfizer vaccine is less effective against the new strain.

While the findings released are preliminary and have not been peer-reviewed, they line up with other early data about omicron’s behavior, including that it seems to be more easily transmitted.

The U.K. Health Security Agency said Friday that new data from the U.K. confirm that omicron is more easily transmissible than other variants.

Other studies suggest that both the AstraZeneca and Pfizer vaccines are less effective in preventing symptomatic infections in people exposed to omicron, though preliminary data show that effectiveness appears to rise to between 70% and 75% after a third booster dose

The ‘most mutated virus we’d ever seen’

Scientists who’ve gotten a close look at the omicron version of the virus have been saying the variant is really mutated. “This is probably the most mutated virus we’d ever seen,” Alex Sigal told CBS News. Sigal leads a team of researchers working to learn more about omicron.

Of omicron’s many mutations, about 30 of them are on a part of the virus called the spike protein. That concerns scientists because it could affect how transmissible the variant is.

CDC still learning about omicron

The Centers for Disease Control and Prevention (CDC) says it has been collaborating with global public health and industry partners to learn about omicron, as its experts continue to monitor the variant’s course. CDC has been using genomic surveillance throughout the course of the pandemic to track variants of SARS-CoV-2, the virus that causes COVID-19, and inform public health practice.

“We don’t yet know how easily it spreads, the severity of illness it causes, or how well available vaccines and medications work against it,” the CDC’s omicron page states.

How easily does Omicron spread? The omicron variant likely will spread more easily than the original SARS-CoV-2 virus and how easily omicron spreads compared to Delta remains unknown. CDC expects that anyone with omicron infection can spread the virus to others, even if they are vaccinated or don’t have symptoms.

Vaccines and omicron

The CDC says current vaccines are expected to protect against severe illness, hospitalizations, and deaths due to infection with the omicron variant. However, breakthrough infections in people who are fully vaccinated can occur.

“With other variants, like delta, vaccines have remained effective at preventing severe illness, hospitalizations, and death. The recent emergence of omicron further emphasizes the importance of vaccination and boosters.”

Local experts say very little is still known about omicron

Late last month, WATE 6 On Your Side spoke with Dr. Mark Rasnake with the University of Tennessee Medical Center about the omicron variant, who said the illness starts out with more mild symptoms and make it more difficult to clinically detect.

“Fortunately, the currently available COVID PCR tests can detect this variant and it also apparently has some unique signals on the testing platforms so that people without even sequencing might be able to get some early signs that that variant is present,” Rasnake explained.

The main takeaway was that the variant had been detected early and information was shared out quickly, but there was still a lot to learn, at the time. He also said the next couple of weeks will shed light on how much the vaccine can protect people against the variant, as well as how contagious the variant may be.

Previously published content from Nexstar Media Wire and The Associated Press contributed to this report.