The only COVID-19 vaccine offered to the majority of older Australians provides next to no protection against the Omicron variant leaving millions exposed, experts are warning.
Evidence is growing that only the Pfizer and Moderna vaccines, and not the AstraZeneca vaccine given to most older Australians, provide any kind of protection against the new variant.
With those aged over 60 effectively barred from receiving the Pfizer and Moderna vaccines during the earlier stages of the pandemic, the federal government’s vaccine rollout program may have left Australians aged 60-plus vulnerable to the current wave.
Evidence suggests all vaccines still provide good protection against serious illness from Omicron, but only the mRNA-based vaccines (when reinforced by a booster dose) appear to have any success at stopping Omicron infection.
The Pfizer and Moderna shots use the mRNA technology, other vaccines are based on older methods of triggering an immune response.
A British study found the Oxford-AstraZeneca vaccine “showed no ability to stop Omicron infection six months after vaccination”, the New York Times reports.
The majority of older Australians were offered only AstraZeneca, which led to vaccine hesitancy and complaints that they were being discriminated against.
Researchers from the University of NSW have outlined preprint lab results – preliminary versions of scientific manuscripts shared before peer reviews – that show two doses of any of the current vaccines offer virtually no protection from Omicron, but that a booster shot could provide some immunity from infection.
“Neither vaccination with two doses of AstraZeneca nor Pfizer were able to stimulate an antibody response strong enough to neutralise Omicron in our assays among the samples we tested,” said study co-author Dr Stuart Turville.
“This is significant and supports the need for boosters to protect from infection.”
But it’s not time to hit the panic button just yet. While the current vaccines may not be able to prevent the spread of the new variant, the evidence still suggests being double-vaccinated will provide good protection against the worst symptoms – hospitalisation and death.
“The preliminary data about Omicron and vaccines is coming in quickly and is revealing lower vaccine effectiveness,” says epidemiologist Professor Melissa Hawkins.
“Best estimates suggest vaccines are around 30-40 per cent effective at preventing infections and 70 per cent effective at preventing severe disease.”
There is also continuing preliminary data coming out of South Africa, the nation where Omicron was first detected, that suggests Omicron may produce milder symptoms than previous variants. There, COVID-19 hospitalisations are down 29 per cent compared with the wave that hit the country in mid-2020.
Still, the rapid spread of Omicron has heaped pressure on health systems in the northern hemisphere, with many countries now looking to reintroduce restrictions.
Prime Minister Scott Morrison seems determined not to let that happen here, saying he will “not allow” the country to return to rolling lockdowns.
“We’re not going back to lockdowns, none of us want that,” Mr Morrison told the ABC.
“We need to make calm decisions and not get spooked by this.”
Federal health minister Greg Hunt agreed, saying he believed health authorities in Australia had the situation under control.
“We’re going into summer and we have one of the highest vaccination rates in the world and a very different set of circumstances,” he told SBS.
“We don’t see that that’s [introducing restrictions] a likely situation in Australia.”
Are you worried about the spread of the Omicron variant? Or is it time to learn to live with the virus? Let us know your thoughts in the comments section below.
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