The spread of a new COVID-19 variant will be revealed in the latest weekly case numbers as Australia enforces strict travel rules on visitors from China.

Just eight cases of the XBB.1.5 variant have been detected in Australia at last count, but health authorities are on guard after it ripped through the US.

There is no evidence the new variant is more severe than previous iterations, but the World Health Organisation says it is concerned about XBB.1.5 given how easily it can be shared.

“It is the most transmissible subvariant that has been detected yet,” WHO COVID lead Maria Van Kerkhove said.

“We do expect further waves of infection around the world, but that doesn’t have to translate into further waves of death because our countermeasures continue to work.”

Only 1 per cent of NSW cases tested for genomic sequence in the past fortnight have been XBB.1.5.

American data says the variant is responsible for 40 per cent of that country’s new cases. It is unclear if XBB.1.5 has had a similar impact in China, given Beijing’s reluctance to share data.

Health Minister Mark Butler said he had asked his department to contact its Chinese equivalent and encourage more transparency with information.

“It would be valuable for information to be shared more comprehensively by China not just with Australia, but with the rest of the world in the way in which other countries are doing real time offloading of their genomic sequencing of COVID cases,” he said on Thursday.

Australia requires travellers from China to produce a negative COVID test before departure.

Australia-China Relations Institute research principal Roc Shi said Beijing might have initially bristled at the rule, but negative trade ramifications were unlikely to follow.

“The Australian COVID travel restriction, while having some controversy, is the same as the Chinese COVID travel restriction,” he said.

“Even if there is some unhappiness, the Chinese side is unlikely to initiate new trade restrictions given the positive atmosphere to improve the relationship.”

The latest weekly COVID-19 data released on Friday show cases continuing to fall in Victoria and NSW but deaths rising.

Victoria had 12,349 new infections and 108 deaths in the seven days to Friday after 16,568 cases and 69 deaths the previous week.

It was a similar story in NSW as weekly reported cases to Thursday afternoon dropped to 19,793 from 27,665 the previous week, while deaths more than doubled from 32 to 77.

Weekly virus data by jurisdiction

• Victoria: 12,349 cases, 108 deaths
• NSW: 19,793 cases, 69 deaths

-AAP