In a matter of days, a new coronavirus variant went from unknown to one of concern, putting the world on high alert and snarling global travel and holiday plans in the process.
Omicron, as it’s called, was first linked to a rise in COVID-19 cases in South Africa and has since been driving a spike in infections in the U.S. and several other countries. Scientists are racing to learn more about the new strain, including whether it can cause more severe disease. Here’s what we know so far about omicron — plus tips for keeping yourself safe as it spreads.
A multitude of mutations makes it stand out
Viruses change and evolve as they circulate, so variations of the original version are expected. “You might think of it as a new cousin in the family,” says William Schaffner, M.D., a professor in the Division of Infectious Diseases at Vanderbilt University School of Medicine.
Omicron, however, has what top infectious disease expert Anthony Fauci, M.D., calls “a very unusual constellation of changes" compared to previous coronavirus strains.
Delta — the variant that rose to dominance over the summer and is still responsible for roughly a quarter of new COVID-19 cases in the U.S. — has about 10 mutations on the all-important spike protein part of the virus, says Egon Ozer, M.D., an assistant professor at Northwestern’s Feinberg School of Medicine and director of the Center for Pathogen Genomics and Microbial Evolution in the Havey Institute for Global Health.
Omicron, on the other hand, has more than 30 mutations on the spike protein alone, and around 50 in total. “This is not delta,” Fauci emphasized in a White House news briefing. “It's something different.”