A person who travelled from South Africa into NSW has been identified as the first person in Australia with the BA.4 sub-variant of Omicron, while Victoria’s health department has detected the BA.2.12.1 Omicron strain in Melbourne wastewater.
The BA.4 strain, declared a variant of concern by the WHO, has been linked to an uptick in cases in South Africa. The country has been recording approximately 4000 to 6000 COVID-19 cases a day in the past few days, up from a few hundred just a few weeks ago.
Former World Health Organization adviser Adrian Esterman said the emergence of the two new strains in Australia will likely lead to more COVID-19 cases because they are “much stronger” than the current dominant strain BA.2.
“What we know about BA.4 is that it appears to escape the immune system a bit better than BA.2, so that means that people who’ve already been infected can be re-infected more easily, and people who are vaccinated can be infected more easily,” University of South Australia epidemiologist Esterman said.
“This comes just at the stage we’re removing all our public health measures. That’s the bad news.
“The good news is so many people have been infected now and those who haven’t been infected probably have quite good immune systems from being vaccinated, so we have got a bit of protection from major increases in cases from these two sub-variants.”