Australia is currently in the throes of another COVID wave. After seeing the anticipated spike in cases throughout Winter, COVID is once again back on the rise thanks to two emerging new strains that are extremely transmissible.
As a result of this, Western Australia Premier Roger Cook announced that as of Monday November 20, mask wearing will be mandatory for staff and patients in “high-risk” zones of hospitals.
Here’s everything you need to know about the latest COVID wave.
How do we know we’re in the midst of another wave?
Gone are the days where we knew with pinpoint accuracy the exact number of COVID cases around Australia. As lockdowns ended and restrictions eased, people began testing less which makes tracking the number of cases significantly harder.
However, in the absence of concrete case numbers, a more insightful indicator of COVID trends has become the number of prescriptions for COVID-specific antiviral medications such as ritonavir (Paxlovid) and molnupiravir (Lagevrio) on the Pharmaceutical Benefits Scheme (PBS).
According to national prescribing data from the national health department, COVID-specific antiviral subscriptions for November 2023 (approximately 38,000) are almost as high as the winter peak in June 2023 (Approximately 80,000).
Why are we experiencing another wave now?
At its core a virus’ one goal is to replicate. Viruses like COVID mutate as they replicate from host to host in order to evade immunity, which is how we end up with variants and strains such as Alpha, Beta, Delta and Omicron.
The two strains going around currently are Eris and Pirola, which are mutations of Omicron – which became the dominant variant back in 2021.
According to Professor Nathan Bartlett, who is a Virologist with the Hunter Medical Research Institute, Pirola is not what’s causing Australia’s spike in cases, rather it is the Eris mutation.
“The primary of our lineage in Australia this year has been based on XBB (Omicron)… it seems the virus has settled on Omicron as being the subtypes that provides it with optimal conditions to get into your cells and to replicate, but also has the ability to still evade immunity through mutation.”
What is the new Pirola variant?
On the other hand, Pirola is relatively newer and was first reported in Denmark in August 2023. Professor Bartlett says that whilst Pirola is currently not responsible for the uptick in cases, it has become a variant of interest around the world because it has 30 genetic changes from its parent which is B82 variant.
“A lot of the other variants we have seen only had one or two mutations which just changed that spike a little bit and gave it an edge in terms of immune evasion.
“Pirola has many more mutations than we’ve previously seen which may see a major change in the way Omicron behaves with all these new mutations.
“But for now, it hasn’t really been very influential in Australia.”
What vaccines are available?
Professor Bartlett says that the spike in cases is not the result of socialising, or Australians just going about life as normal, but rather the drop off in booster rates.
“People are not going for their boosters as much as what they might have done a couple of years ago. This is coinciding with a time where variants of the virus are mutating to be immune evasive, which gives the virus an edge.”
The Therapeutic Goods Administration has recently approved XBB.1.5-specific monovalent vaccines which are projected to have better long-term protection against Omicron variants rather than the currently available bivalent vaccines.
However, the traditional bivalent vaccines can still protect against both the original ancestral strain of SARS-CoV-2 as well as the new COVID variants. Similarly, these bivalent vaccines can also protect people from severe ramifications from Omicron variants.
