Australia defends using Oxford vaccine

Health officials in Australia were moved to defend the country's COVID-19 immunization strategy after scientists questioned its reliance on the vaccine from Oxford University and AstraZeneca.

The so-called Oxford vaccine will be central to the first phase of Australia's immunization drive, as the nation has a deal in place for 54 million doses, 3.8 million of which are being made available early this year.

But several experts, including Stephen Turner, who is president of the Australian and New Zealand Society for Immunology, or ASI, said that the so-called Oxford vaccine compares unfavorably with other available treatments in terms of efficacy.

"The AstraZeneca vaccine is not one I would be deploying widely, because of that lower efficacy. You cannot rely on it to establish herd immunity," Turner said in an article published in Melbourne-based newspaper The Age on Tuesday. "Given we have fantastic vaccines against this, I think it would be wise to not rely on the AstraZeneca vaccine for controlling the virus in Australia."

Interim results showed that the Oxford vaccine was 62 percent effective in preventing COVID-19 infection after two full doses. Efficacy reached 90 percent among trial participants who were mistakenly given a half dose followed by a full dose.

Turner and others asked why the Australian government would proceed with a campaign so heavily reliant on the Oxford jab, when separate treatments from both Pfizer and Moderna posted more impressive trial results of 90 percent efficacy or above.

Australia's Chief Medical Officer Paul Kelly said on Wednesday he backed the safety and efficacy results from the Oxford trials, adding that Australia does not have the ability to make the Pfizer treatment, whereas the Oxford jab can be manufactured in large quantities domestically.

"We're not in any queue for those," Kelly said. "The choice is not whether one is better than the other; it is which one is available to give the maximum rollout of vaccine to save lives and to protect lives this year. The answer to that is the one we can make here."

Australia's second-largest deal for the supply of COVID-19 vaccines is with Novavax, for 51 million doses, though this vaccine candidate is still in trials. The nation also has a 10 million dose deal in place with Pfizer.

On Tuesday, the Australasian Virology Society confirmed to The Age that it recommended a pause to the rollout of the Oxford vaccine, though it later changed its position and no longer opposes the rollout.

The ASI released a statement following Turner's interview with the newspaper, in which it said the body "does not advocate a pause on the rollout" of the Oxford vaccine.

Allen Cheng, who is president of the Australasian Society for Infectious Diseases, said that the main advantage of the Oxford vaccine is that Australia can roll it out quickly.

"Even if it doesn't protect against transmission, it does protect against disease and that's a benefit," Cheng said on Twitter. "The choice we have isn't whether to use one vaccine or the other. Our choice is whether to offer everything we have now to protect as many people as we can, or to leave some effective vaccines in the warehouse."