Coronavirus case rates have been accelerating since mid-June, driven in part by the dominant and more contagious delta variant.
Now, ASU virologist Efrim Lim has detected two cases of the mu variant in Arizona.
The World Health Organization's newest variant of interest, mu has mutations that could make it more transmissible and better at escaping vaccines and immune responses, but it is not yet a variant of concern.
ASU Biodesign director Joshua LaBaer says it might never rise to that level.
"But it has a number of mutations that at least theoretically suggest that it could evade the immune system and be good at transmission," he said.
LaBaer said the variant is concerning, at least on paper, because it has aspects that resemble delta for transmissibility and Beta for its capacity to evade the immune system. But he added that vaccines were very effective in countries where beta dominated.
Hear Steve Goldstein And Mark Brodie Discuss Delta And Mu Variants On The Show
"We don't have the data yet. It's all theoretical at the moment. There is some reason to believe that the vaccines will still work there. But as I said, it's only a matter of time before a variant appears where the vaccines don't work as well, and we're going to have to adapt to that," LaBaer said.
He attributes the present surge to delta's transmissibility, high numbers of unvaccinated Americans, and possibly waning resistance from the earliest vaccinations.
