Sydney: A new COVID-19 variant is driving up infections in Australia, with health experts warning that there's potential for this variant to play a significant role in the winter respiratory season, local broadcaster SBS News reported.

According to Anadolu Agency, the new variant, NB.1.8.1., was designated by the WHO as a "variant under monitoring" last week, due to its growing global spread and some notable characteristics which could set it apart from earlier variants. The reduced number of people testing has made it more difficult to track the occurrence of the virus. However, available data suggests that in late May, case numbers were increasing in Australia.

Genomic sequencing has confirmed that NB.1.8.1 is generally increasing in Australia. According to the data sequenced up to May 6 across the country, NB.1.8.1 ranged from less than 10% in South Australia to more than 40% in Victoria. Wastewater surveillance in Western Australia has determined NB.1.8.1 is now the dominant variant in wastewater samples collected in the state capital, Perth.

Internationally, NB.1.8.1 is also growing, particularly in Asia, prompting closer monitoring by international public health agencies. At the end of April, NB.1.8.1 was the dominant variant in Hong Kong and China.

According to the WHO, NB.1.8.1, a sublineage of the Omicron variant, was first detected in samples collected in January 2025. The WHO, however, has not yet observed any evidence that it causes more severe disease compared to other variants. Common symptoms of the virus include sore throat, fatigue, fever, mild cough, muscle aches, and nasal congestion, with gastrointestinal symptoms occurring in some cases.