The understanding of the new Omicron variant is changing day by day, but the core message of the experts remains constant: boosters are key.
In an ultra-secure lab at the Kirby Institute at UNSW, a team of researchers have been working to understand the effectiveness of vaccines against the Omicron variant – and the first round of data is in.
Dr Stuart Turville, associate professor in the immunovirology and pathogenesis program at the Kirby Institute UNSW, spoke to the media on Wednesday, confirming that immunity derived from two-dose vaccination is insufficient to prevent infection from Omicron.
“It changed to avoid antibodies,” he said.
“… it had a very big gear change in how it sticks to cells… it also had the third gear that helps it spread in the community.”
During their study, the researchers used three different methods to test how the variant stacks up against immunity from vaccination versus natural infection.
This included natural infection only, two-dose vaccine only and a combination of both previous infection and two dose-vaccination.
In all cases, the Omicron was seen to evade immunity.
“We are not distinguishing between the vaccines because we know we see the same result… Zero protection with the antibodies from double-dose vaccination,” Turville said.
Whilst these results may be cause for concern, Professor Anthony Kelleher, director of the Kirby Institute, notes that these preliminary assays do not provide a full understanding of how live persons’ immune responses will function.
“There are also T-cells that play an important role,” he said.
Dr Deborah Cromer, group leader in infection epidemiology and policy analytics at the Kirby Institute, says that although these studies show Omicron to be quite evasive, there is no evidence yet to suggest there is a higher risk of mortality from the variant.
“What we see is whilst there is very limited vaccine protection against symptomatic infection… but there is still some protection against severe disease and hospitalisation.”
Cromer told Aged Care News that the aged care community should not panic, but prioritise receiving a m-RNA booster vaccine as soon as possible.
“Older people are in general have neutralising antibody responses that are lower than the average… [but] getting a booster dose will still provide a high level of protection against Omicron,” she said.
“Vaccination with the MRNA dose… provides 98 per cent protection against severe disease.”
Turville added that further research is in progress to understand the unique susceptibility of older and immunocompromised individuals.
And apart from vaccination, one therapeutic intervention was shown to hold up against the new variant.
“The positive data that we’ve seen is that sotrovimab is still effective against Omicron.”
Sotrovimab is a monoclonal antibody medication that binds to the spike protein of the SARS-Cov-2 virus, available as an intravenous infusion to those who have developed COVID-19 and are at a high risk of severe disease and/or death.
This news comes as the Australian Technical Advisory Group on Immunisation (ATAGI) updated its guidelines, now recommending that boosters be received five months after the completion of the primary schedule.
“People who live and work in residential aged care are strongly encouraged to get a booster dose as soon as they are eligible,” a health department spokesperson said in a statement issued Monday.
“The anticipated benefits of bringing forward the booster dose include earlier protection, particularly against severe disease in those at risk, and improved protection against COVID-19 due to the Omicron variant,”
The booster programme has been rolling out in residential aged care facilities (RACF) since October, with 900 clinics across the country currently delivering Pfizer (Cominarty) m-RNA booster shots to eligible residents and workers.
In addition, the Moderna (Spikevax) m-RNA vaccine has now been approved as a booster shot option, available through selected pharmacies and general practices.
As of December 14, a total of 771,682 people aged over 16 have received a third dose of the vaccine so far.
Aged Care News has contacted the federal health department for further information on the status of the rollout within RACFs.