New Covid-19 wave to hit NSW within weeks, chief health officer says

Chant is expected on Thursday to reiterate the importance of getting booster doses, and will again urge those most at risk of severe disease to plan ahead by talking to their doctor about the antivirals available to reduce the severity of infection.

She will also urge people to stay home if they have cold or flu-like symptoms and ask those who must leave the house while unwell to wear a mask when indoors or on public transport. They should avoid large gatherings and high-risk settings, such as hospitals and aged or disability care facilities, for at least seven days.

The World Health Organization does not consider the two subvariants as different enough from other circulating Omicron subvariants to warrant their classification as new variants of concern. But the two sublineages remain part of Omicron, which is a variant of concern.

The WHO has said there is no epidemiological data to suggest an increase in disease severity due to the variants.

The latest NSW respiratory diseases surveillance report, with an overview of Covid cases, will be published later on Thursday.

Meanwhile, results from two complementary national serosurveys, one in children and adolescents and one in adults, were published on Thursday to provide a snapshot of the extent of infections across Australia to the end of August.

Serosurveys involve conducting tests on blood samples taken from thousands of Australians across various age groups, geographical locations and target populations. Researchers look for antibodies to the virus in the blood to determine the extent a population has been affected.

The children and adolescents survey found at least 64% of 0 to 19-year-olds in Australia had been infected with Covid-19.

In children aged one to four years old, approximately eight out of 10 had evidence of past infection. This group was not eligible for vaccination at the time of the serosurveys; however, high-risk, severely immunocompromised children aged six months to four years became eligible for vaccination from September.

The adult study found at least 65% of adults in Australia had been infected by the virus, similar to the proportion of children and adolescents.