Three new sub-variants of Omicron have reached Australia and health authorities say people who contract the virus should wait three months before receiving their next Covid-19 vaccination.
Associate Professor Stuart Turville of the Kirby Institute at the University of New South Wales says Omicron sub-variants BA.2.12.1, BA.4 and BA.5 have been detected in the country.
Authorities are warning that this winter season is likely to see a spike in Covid-19 and flu cases as restrictions that have suppressed the circulation of the two viruses are phased out.
The latest advice from the Australian Immunization Technical Advisory Group recommends people wait three months after a confirmed Covid-19 infection and then receive their next dose of vaccine as soon as possible.
The advisory, issued last week, applies to all people and for all Covid-19 vaccines.
Turville said the severity and transmissibility of the new Omicron subvariants have yet to be determined.
The arrival of Omicron BA.1 and BA.2 was marked by their ability to significantly escape a previous antibody response through previous infection and/or vaccination, but the impact has been less severe.
New sub-variants BA.4, BA.5 and BA2.12.1 are likely to replace BA.1 and BA.2 in Australia.
“We will need to study this over time to see if their benefit is one of ‘fitness/transmissibility’ and/or their ability to be more slippery for existing antibodies,” Turville said. “As with all variants, the key parameter to monitor is the severity of the disease and this data takes time to accumulate.
“There is still a lot about this virus that is unknown and there are many paths it has the potential to take.”