Omicron BA.4 and BA.2.12.1, Discovered in Australia, Raising Concerns about New Surge

The initial Omicron variant has been Australia's dominant strain since its arrival in November 2021. Since the discovery of Omicron in November 2021, Australia has recorded tens of thousands of cases every day. It was later discovered that it is far more infectious than previous Covid strains but far less dangerous than Delta.

Authorities in Australia have discovered two new Covid variants that are "highly transmissible" compared to the current dominant strain.

A traveller from South Africa to NSW was discovered to have the BA. 4 sub-variant of Omicron – the first known case of its kind in Australia.

The BA. 2.12.1 Omicron strain was also discovered in Melbourne wastewater by testing facilities.

The newly discovered strains were "more dominant" than their predecessors due to their much higher transmissibility, potentially causing a new spike in cases globally. BA. 4 appears to evade the immune system slightly better than BA. 2, allowing previously infected individuals to be reinfected and vaccinated individuals to become infected more easily. This occurs at a time when all of our public health measures are being dismantled.

The case was discovered on Thursday after the traveller arrived in Australia in the first week of April through a PCR test.

NSW Health is closely monitoring the situation and has stated that because this is not a random sample, the proportion of identified variants may not be representative of their distribution in the community.