Australians are being urged to get their COVID-19 booster as a new coronavirus variant drives up infections.
The World Health Organization (WHO) has designated the new NB.1.8.1 strain as a "variant under monitoring" and it's now the dominant variant in China and Hong Kong.
Griffith University virologist Associate Professor Lara Herrero said the new strain could possibly overtake others in Australia too.
"The new strain is now the dominant coronavirus strain in China and Hong Kong and, in Australia, we're seeing it pretty much everywhere.
"There is a prediction that this might start taking over other strains, but it's early days, so we'll just wait and see."
Currently the new variant makes up more than 40 per cent of total COVID cases tested in Victoria, around 25 per cent in Western Australia and New South Wales, around 20 per cent in Queensland and less than 10 per cent in South Australia.
"We're seeing a lot of cases in the community coming through the [emergency department] but it's likely we're heavily under-reporting because COVID reporting is no longer mandatory," Dr Herrero said.
Health Minister Mark Butler is encouraging Australians to get the COVID booster.
"I do encourage, particularly as we head into winter, for people to think about the last time they got a COVID vaccine," he said.
"Older Australians are strongly encouraged and recommended to get that booster. But certainly everyone else is eligible for a free COVID booster, if they've not had one in the last 12 months at their local pharmacy or GP."
New strain could spread more easily
More than five years since COVID was declared a pandemic, Australia is still experiencing regular infections and Dr Herrero said case numbers had been slowly rising since May.
In the past six months, only 6.6 per cent of adults have received a COVID vaccine, according to federal data.
"This new strain is a sublineage of Omicron and descends from the JN1 variant, which is what the current vaccine protects against," she said.
"The flu is nasty this season too so I'd very strongly recommend everyone get their yearly flu vaccine and JN1 COVID booster — it's the best way you're going to be protected if you haven't had COVID in the last six months.
"As the virus mutates, it gets a little sneakier and better at evading our immune response and antibodies."
Australian Medical Association NSW chair of public health Dr Michael Bonning said early reports showed the variant had a higher infection rate, but that existing vaccines were still effective.
"Individual variants are probably less important than overall societal factors such as whether people are keeping up to date with boosters," he said.
Dr Bonning said respiratory infections were up nationally.
"We are expecting a spike in cases over the coming weeks with an expectation of a particularly difficult winter respiratory season because of what we have seen in the northern hemisphere," he said.
"In New South Wales, in the past week there was an increase of 29.2 per cent in COVID-19 notifications, an increase of 25.9 per cent in influenza notifications, and an increase of 9.7 per cent in RSV notifications."
According to WHO, NB.1.8.1 was first detected in January. It was declared a variant under monitoring earlier this month.
"That is not done with every variant — not at all — it's ones that have specific mutations or if we have extra data that it might evade the immune system or transmit better," Dr Herrero said.
"In this case, we've got mutations in the spike protein that seems to be making it easier for this virus to attach to our cells and it seems to be making this virus evade our antibodies better."
No change in symptoms
Dr Herraro said there was no evidence to suggest the symptoms of the new strain were worse than other variants.
"We're still seeing the same symptoms like fevers, cough, runny nose, headaches, some people are getting whole body aches and some are getting gastro symptoms," she said.
"We're probably all getting tired of these sorts of messages but I'd just say to people, just be vigilant before you get sick because that's how you protect yourself.
"Wash your hands, don't go out in public if you're sick and spread it to everyone, get your vaccines if you want them. If you've got a cough or cold I'd wear a mask because you don't want to share that with other people."
Infectious diseases physician Paul Griffin said COVID vaccination rates were "terribly low", despite hospitalisations and deaths continuing.
“We definitely need to get the message out there that COVID vaccines remain important, especially as we now have a new subvariant that looks more infectious and is spreading rapidly around the world," he said.
“Most people do under appreciate the risk from COVID. Severe disease and deaths do occur and we’ve already lost 500 people due to COVID this year and that’s why we need to try and reduce the impact.”
