STOCKTON, Calif — First detected in Colombia back in January 2021, the mu variant of COVID-19 recently became a "variant of concern" by the World Health Organization [WHO] in August.
There are concerns it could make vaccines and treatments less effective, however, more case studies are needed.
Globally, the mu variant makes up only 1% of cases, according to the Center for Viral Systems Biology at Scripps Research. The delta variant makes up 99% of the rest.
In California, there have been 399 cases detected. No cases have been discovered in Sacramento, San Joaquin or Stanislaus Counties. However, one case has been detected in Placer County.
So, how concerned should people be? ABC10 asked San Joaquin County Public Health Officer Dr. Maggie Park.
"We're watching it closely, but it's not yet a variant of concern. A variant of concern like the delta variant is one in which we know for sure and there's evidence that it is more transmissible, or that it does actually evade vaccines or have some other components to it," Dr. Park said.
The other question at hand is whether COVID-19 vaccines will hold up against the mu variant.
"Some studies in other countries where the new variant has existed that the vaccines we have here in the United States should be effective against the new variant. But, there's not a whole lot of studies - nothing to really hang our hat on. We're hoping that our vaccines are going to be effective as they have been against the delta variant," said Park.
Dr. Anthony Fauci, the top U.S. infectious disease expert, tells the Associated Press the U.S. "is paying attention to it. But it isn't considered an immediate threat."
Dr. Park says its another reason to get a booster shot, if and when they become available.
"This virus is going to keep mutating. It's going to keep showing its leader of all the variants (that) will emerge. Dominant strains will keep emerging," she said.
WATCH ALSO: