A newly emerging strain of the Covid-19 virus, which has recently driven a surge in infections across China, Taiwan, and Hong Kong, has now been detected in Australia.

The variant, designated NB.1.8.1, was first identified on January 21 and was added to the World Health Organization’s (WHO) watchlist on May 23 due to its rapid spread. In Western Australia, recent wastewater testing in Perth has revealed that NB.1.8.1 has become the dominant strain in the region. Health officials believe it is likely responsible for a 24 percent increase in daily average Covid cases last week, with numbers rising to 38 cases per day.

Authorities in the United States have also confirmed the presence of the NB.1.8.1 variant at several airports across the country and within local communities in Hawaii, Rhode Island, and Ohio. According to the WHO, while this variant appears to spread more easily than other strains, current data suggests it does not cause more severe illness.

“Despite a concurrent rise in cases and hospitalisations in regions where NB.1.8.1 is widespread, there is no current evidence that this variant leads to more serious disease than others currently in circulation,” the organization stated on Friday.

Reported symptoms associated with the NB.1.8.1 variant include cough, sore throat, nausea, dizziness, loss of appetite, blurred vision, fatigue, difficulty concentrating, and elevated body temperature (hyperthermia).

Health officials in Hong Kong have reported a “significant increase” in Covid-19 cases due to this variant, marking the highest case levels in over a year. Over the past month, the city has recorded 81 severe cases. In mainland China, the number of emergency room visits related to Covid has doubled in recent weeks, with the hospitalization rate now standing at approximately 6 percent.

Dr. Edwin Tsui, Director of Hong Kong’s Centre for Health Protection (CHP), cautioned that the variant should not be underestimated. He emphasized that NB.1.8.1, a sub-lineage of the Omicron variant, might be developing increased resistance to existing vaccines.

“The CHP will continue to monitor developments closely in accordance with WHO guidance,” Dr. Tsui said. “We must remain vigilant about the potential emergence of more virulent or vaccine-resistant strains.”

In response to the rising cases, Hong Kong officials have renewed public health guidance, urging individuals at higher risk of infection to wear masks in public settings. They also recommended mask usage on public transportation and in crowded indoor areas.

Meanwhile, Western Australia is also experiencing a surge in influenza cases. State health authorities are encouraging all residents, especially seniors and those with pre-existing health conditions, to get vaccinated. Free flu vaccines are currently available for individuals over the age of 65, including visitors to the state.

In contrast, the United States announced a significant policy shift this week: it will no longer recommend Covid-19 vaccinations for children and healthy pregnant women, a move that has sparked discussion among medical professionals and public health experts.