Major stock indices on U.S. markets were down on Wednesday after the U.S. Centers for Disease Control and Prevention (CDC) confirmed the first case of Omicron COVID-19 variant in the United States.

"The California and San Francisco Departments of Public Health have confirmed that a recent case of COVID-19 among an individual in California was caused by the Omicron variant," the CDC wrote yesterday. "The individual had mild symptoms that are improving, is self-quarantining, and has been since testing positive. All close contacts have been contacted and have tested negative."

Wall Street, which has been on pins and needles with anxiety over Omicron, was spooked into a selloff by the announcement. The Dow Jones Industrial Average (DIA  ) dropped 1.9%, while the Nasdaq Composite (QQQ  ) slid by 3.2%. The S&P 500 (SPY  ) tumbled 2% by market close on Wednesday.

Minnesota health authorities confirmed the second case of the Omicron variant on Wednesday. Despite this, markets seem to be recovering. The Dow bounced back 1.82%, while the Nasdaq Composite and S&P 500 recovered 0.83% and 1.42%, respectively, on Thursday.

Given the uncertainty surrounding the Omicron variant, and other factors such as inflation, it's unlikely that this will be the last time Wall Street is spooked into a selloff.

"While it is nice to see a rally this morning, I am not sure investors should put much meaning into it," said Chief Investment Strategist Jim Paulsen of Leuthold Group, in a statement. "While it is nice to see a rally this morning, I am not sure investors should put much meaning into it."

Last week, the World Health Organization classified Omicron as a variant of concern, with the U.S. following soon after. The CDC has been actively monitoring and preparing for Omicron since it was first discovered by scientists in South Africa, with the agency asserting that it will continue to work with other U.S. and global public health authorities to best address the variant's threat. Currently, the Delta variant remains the dominant strain in the U.S.

The White House has begun increasing viral surveillance to track the domestic spread of Omicron. In addition, the Biden Administration is in the process of enacting new travel restrictions. However, these measures aren't likely to stymie market volatility.