Nebraska is the only state in the United States to have not detected a case of the Mu variant of COVID-19, which may render vaccines less effective. Since being first identified in Colombia in January, the Mu variant has spread to 41 countries, including the United States. Most prevalent in Hawaii and Alaska, the variant accounts for less than one percent of cases in the U.S., but its potential to be more transmissible or resist vaccines and natural immunity have health officials keeping tabs on the mutation. At least one case of the Mu variant has been detected in the...