RELATED: These 4 New COVID Symptoms Could Mean You Have Omicron, Doctors Warn. Read the original article on Best Life. Researchers have been working to pinpoint common signs of the Omicron variant over the last few months. Emerging research has been showing that Omicron is more likely to affect the upper respiratory tract instead of the lungs, unlike some prior versions of the virus, according to WHO. This means there has been a break from some of the earlier tell-tale COVID symptoms like loss of smell or taste and shortness of breath.ae0fcc31ae342fd3a1346ebb1f342fcb And Omicron’s BA.2 subvariant might not be much different. According to The Daily Express, there are seven symptoms U.K. researchers have already associated with the new stealth Omicron variant: fever, extreme fatigue, coughing, sore throat, sore head, muscular fatigue, and an elevated heart rate. Some of these fall in line with tell-tale Omicron symptoms. According to the U.K. Zoe COVID Study App, the five most frequently reported signs of the original version of this variant are runny nose, headache, fatigue, sneezing, and sore throat. “The most reported symptoms of Omicron are really very much like a cold, especially in people who’ve been vaccinated,” Claire Steves, PhD, a scientist from King’s College London involved with Zoe, confirmed in a Jan. 6 video. Despite BA.2 being labeled a subvariant of Omicron, there are still significant differences in the genetic makeup of the variants. The stealth variant has about 20 mutations that differ from the original Omicron, according to Francois Balloux, a professor of computational system biology and director of the UCL Genetics Institute in London. “BA.2 has a number of mutations that BA.1 does not have that are in the region of genomes that concerns us,” Jeremy Luban, MD, a professor of molecular medicine, biochemistry, and molecular pharmacology at University of Massachusetts Medical School, told Verywell Health. “It’s like when Omicron first hit. In the first few days, we had a sequence, the sequence itself was terrifying, but it took time before we could find out if Omicron would be more pathogenic and infectious.” RELATED: For more up-to-date information, sign up for our daily newsletter. The stealth Omicron variant has already made its way around several countries including Denmark, India, Sweden, and Singapore, according to Verywell Health. “Last week in Denmark, BA.2 was about 60 percent of the cases. They also have BA.1 but it looks like BA.2 is replacing BA.1,” Luban told the news outlet. “We’re also seeing presence at high levels in certain locations including several countries in Asia.” But it’s also already been reported in several U.S. states, including Washington, Texas,  New York, New Mexico, Utah, and California, per NBC News. And while numbers in the country are still on the lower side, some virus experts have expressed concern that BA.2 could stall the progress that is being made in the U.S. According to the CDC, COVID cases had fallen 20 percent in the last two weeks, despite Omicron’s dominance. “This may mean higher peak infections in places that have yet to peak, and a slowdown in the downward trends in places that have already experienced peak Omicron,” Thomas Peacock, PhD, a virologist at Imperial College London, explain to The New York Times. Other experts say they don’t feel like the emergence of the stealth Omicron variant is any cause for panic. “BA.2 may extend the Omicron wave a little longer, but I don’t think it changes the overall trajectory of the pandemic,” Amesh Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security, told Prevention, adding that “there is no cause for concern with BA.2 as everything you do to handle BA.1 is applicable.” According to the infectious disease expert, this includes making sure you’re fully vaccinated, getting your booster shot when you’re eligible, and wearing a mask in indoor spaces. This might be especially true given the fact that no research has indicated that the subvariant is any more likely to counteract the efficacy of our COVID vaccines. “It’s not like this variant has increased ability to evade vaccine-induced immunity,” Thomas Russo, MD, professor and chief of infectious disease at the University at Buffalo in New York, told Prevention. “I would also predict that there would be significant protection with BA.2 if you had BA.1. I don’t see this moving the dial significantly in terms of posing a new, huge problem.” RELATED: This One Symptom Could Be Your First Sign of Omicron, Doctors Warn.