On Wednesday, Japan health authorities confirmed its first cases of the new mu variant of the coronavirus which was detected in two people arriving into the country through airport screenings.
It was announced that the mu variant was detected in two women who have been identified to be asymptomatic, one, a woman in her 40s who arrived on the 26th of June, from the United Arab Emirates while the other was a woman in her 50s who arrived on July 5 from the U.K.
Neither of the women has displayed symptoms of the virus at the time of detection.
Japan’s health ministry has said it would continue to sustain measures to ensure and prevent the spread of the variant through effective monitoring of situations in other countries.
The health ministry’s announcement follows a recent report about a new sublineage of the delta variant that emerged in Japan in mid-August. Delta, which originated in India, has become the most prevalent variant in Japan.
The ministry has reiterated that all travelers to Japan are required to take a PCR test upon arrival and wait for results and if they test positive, are required to be quarantined in a designated facility or hospitalized depending on their symptoms.
Also, if tested negative, they are required to quarantine for 14 days at home or a designated facility depending on where they have come from.
The World Health Organization has designated the mu variant, as a variant of interest, the second-highest level in its classification of variants.
In its weekly epidemiological update, published on Tuesday, WHO warned that the variant is becoming increasingly prevalent in Colombia and Ecuador and had shown signs of possible resistance to vaccines.
The statement read, “the variant has a constellation of mutations that indicate potential properties of immune escape.” This means that vaccines or antibody treatments may not work as well against the mu strain as they do against the original version of the coronavirus.
The “Mu” variant was first identified in Colombia in January 2021, and since then there have been sporadic reports of cases and outbreaks in South America and Europe, WHO said.
While the global prevalence of Mu among sequenced COVID-19 cases is below 0.1%, its prevalence had consistently increased in Colombia and Ecuador, where it is now responsible for around 39% and 13% of infections, respectively.
Presently, the WHO designates alpha, beta, gamma, and delta as variants of concern, the highest classification and so far, the alpha, beta, delta, gamma, kappa, lambda and mu variants have all been confirmed in Japan.