NSW Health is urging people to keep up to date with their COVID-19 vaccinations and practise COVID-safe behaviours this winter as COVID-19 transmission in the community remains high, according to the latest Respiratory Surveillance Report published today.

The report shows the overall proportion of positive COVID-19 PCR tests likely to be either Omicron BA.4 or BA.5 sub-lineages increased to 35 per cent in the week ending 25 June, compared with 32 per cent in the previous week. There was a total of 55,510 positive COVID-19 tests reported during the week.

Currently, the BA.2 sub-lineage remains the dominant variant of concern circulating in NSW, according to genomic sequencing of positive PCR tests in NSW. However, it is expected BA.4 and BA.5 will become dominant in the coming weeks and are likely to be associated with an increase in COVID-19 infections including an increase in reinfections.

NSW Chief Health Officer Dr Kerry Chant said we need to do all we can to limit the spread of COVID-19 and protect the most vulnerable members of our community.

"There is no evidence yet of a difference in disease severity for those infected with BA.4 and BA.5, but there is evidence that they are better at evading the body's immunity," Dr Chant said.

"Any potential increase in infections will depend on a combination of factors, including immunity levels in the population and behavioural factors, so it is vital that anyone who is eligible for a booster dose who hasn't yet received it does so as soon as possible.

"We all have a role to play in reducing the spread and burden of respiratory infections this winter and protecting our most vulnerable so I strongly encourage everyone to keep doing the little things that make a big difference, such as staying home when you are sick, washing your hands regularly and indoor mask-wearing."

Dr Chant said before you test positive to COVID-19 you should be aware if you would be eligible for antiviral medications.

"Have a conversation with your doctor and have a plan to manage winter respiratory illnesses. Antivirals work best when taken as soon as possible, usually within five days from when your symptoms start," Dr Chant said.

We can all help reduce the risk to ourselves and others by:

• staying home if we're unwell, taking a COVID-19 test straight away and self-isolating
• wearing a mask indoors or wherever we can't physically distance
• getting together outdoors or in large, well-ventilated spaces with open doors and windows
• practising good hygiene by washing or sanitising our hands often
• taking a rapid antigen test to test for COVID-19 before visiting vulnerable loved ones or going to large gatherings and events
• staying up to date with our vaccinations – for both flu and COVID-19.

COVID-19 booster doses are recommended for everyone 16 years and older who had their last dose of a primary course at least three months ago.

To find your nearest vaccination clinic, visit Find a vaccine clinic.