This is a corrected version of a previous Conversation article that was published on Medical Observer on 20 July which contained incorrect estimates for the basic reproduction number (R0) for COVID-19 subvariants BA.4, BA.5 and BA.2.

Australia is heading for its third Omicron wave in the coming weeks, as BA.4 and BA.5 become the dominant COVID-19 strains.

BA.4 and BA.5 are more infectious than previous COVID-19 variants and subvariants and are better able to evade immunity from vaccines and previous infections.

So we’re likely to see a rise in case numbers.