COVID-19 cases are again on the rise across Australia, with the latest Omicron sub-variant BA.4/BA.5 on track to become the major strain, amid warnings of reinfections and increased hospitalisations.

BA.4/BA.5 represented more than 30% of specimens in NSW in the week ending 18 June, up from 23% the previous week, according to the state’s respiratory surveillance reports.

A similar pattern has emerged in Queensland, while traces of BA.4/BA.5 in Victoria’s metro and regional wastewater have “risen significantly, indicating increasing transmission”, according to Chief Health Officer Brett Sutton.

First identified in catchments in April, the variant now accounts for 17% of Victorian infections and is forecast to overtake BA.2 as the state’s dominant strain within weeks.