The meaning of living with Covid has changed.
Omicron has taken this to a different level and we had been prepared for it. Avaccine-escape looks like this.
As we watched the Delta outbreak in New South Wales and Victoria slowly come under control in 2021 with the rise in the number of people completing our primary course of vaccine, we had every reason to be optimistic for some relief over summer.
Australians over the age of 70 have access to Covid treatments.
The year ended before Omicron arrived.
After taking off in South Africa, Omicron went around the world, peaking in Australia on January 14th. It was able to establish waves quickly wherever it landed, and not just because it was better at spreading. The ability to evade our immunity is what makes it successful.
Prior infections and vaccinations do not provide much protection from this variant. This is immune escapism, which comes from being physically different enough from other variant that our immune system doesn't immediately recognise them to mount an attack, and Omicron is a bigger step change than we saw in the previous immune escape creeps with Delta.
Immune escape undermines the immune system's ability to ward off an infection, but luckily we still have enough cross immunity from vaccine, infection, or both to reduce our risk of serious illness. We had more than 50 times the infections reported in the Delta wave, but only one third of the people in the intensive care unit.
The Omicron variant does boost our immunity against coronaviruses but not against Omicron. Even though you are less likely to get Delta after an Omicron infection, it's still possible to get it again.
Omicron can hold on to the centre stage by actively elbowing out other versions.
The upside is that this could also knock out other bad Mutants that never get a foothold. It is the ability to cause re infections in people who have recently had an illness that keeps Omicron infections high.
The booster vaccine dose became important for everyone when Omicron arrived.
It protects against waning immunity as well as elicits a different type of immune response than the first dose. It increases protection from serious illness back up to the levels seen with Delta, restores some protection from infections, and reduces infections for the first few months.
Reducing risk might be the difference between having an exposure and having an infection
The impact on controlling the Delta outbreak was not as great as it could have been.
The same challenge is faced across the globe as we find ourselves in this new world of infections. As the northern hemisphere went into summer, we were in front of France, New Zealand and Singapore. European countries still in summer have the highest new death reports per capita in the world.
Half of New Zealand's daily death rate is us.
The death rate in Australia has gone up with successive Omicron waves, but is still below the peak rate of three deaths per million. When the first Omicron wave hit, death rates ranged from four to 18 per million.
We are doing well even though we face Omicron in winter.
Singapore, Taiwan and New Zealand are the only countries that have less than 400 deaths per million people.
Canada, France, UK, and the US have all seen over 1,000 deaths per million Americans.
It doesn't make the news that we have had more than 10,000 Covid-19 deaths in Australia any easier, but we have also saved many lives.
We would have had over 30,000 Covid-19 deaths in Australia by now if we matched Canada or the Danes.
In a population the size of Australia, the death rate in Sweden is nearly 50,000.
What do you think will happen next?
We might keep a lid on the wave if everyone gets a booster tomorrow. If everyone had their winter dose, we would see less people end up in the hospital as infections increase.
We are exposed most places we go in larger cities because there is no guarantee that you can prevent infections. Reducing risk may be more important than having an exposure. Between having one or many infections.
It's possible to double or triple the number of active cases reported per 100,000 people in Victoria. Between 1 and 2% of the population.
Many will not even know they are sick.
In the last four weeks, there have been more than 100 cases per thousand in the metropolitan area. It is possible that up to 25% of the population have been affected by a recent infection.
General precautions and masks won't stop Omicron, but they will help us get through the winter.
It is important for people who are at risk of serious illnesses to use antivirals. We will be able to undermine Omicron's main weapon, reinfection, if we can keep a lid on infections.
Catherine Bennett is a professor at the university.
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