Health Minister Greg Hunt stands by COVID-19 vaccine strategy

Australia will not adjust its vaccine strategy despite evidence the AstraZeneca jab is not effective in preventing mild and moderate disease from the South African coronavirus variant.

Health Minister Greg Hunt. Picture: Martin Ollman

Australia will not adjust its vaccine strategy despite evidence the AstraZeneca jab is not effective in preventing mild and moderate disease from the South African coronavirus variant, with the federal government confident it will still protect against severe disease.

But some scientists say there is currently not enough data to assess whether that will be the case, with concerns efficacy may also be reduced in the SA variant against severe disease and death.

Responding to the early results of a small South African study that showed its jab was ineffective against the SA variant, AstraZeneca said it was confident patients would be protected against severe disease.

“We do believe our vaccine will still protect against severe disease, as neutralising antibody activity is equivalent to other COVID-19 vaccines that have demonstrated activity against more severe disease, particularly when the dosing interval is optimised to eight to 12 weeks,” AstraZeneca said in a statement.

Health Minister Greg Hunt said he had received advice from Chief Medical Officer Paul Kelly as well as the Science and Technical Advisory Group, chaired by Health Department secretary Brendan Murphy, that there was “no evidence” the vaccine would be ineffective against severe disease and death from COVID-19 regardless of the variants.

“The advice is very, very clear and that is there’s currently no evidence to indicate a reduction in the effectiveness of either the AstraZeneca or the Pfizer vaccines in preventing severe disease and death,” Mr Hunt said.

“There will be challenges but our fundamental direction is absolutely clear. The vaccine program in Australia continues to be on track.”

Australia has ordered 53 million doses of the AstraZeneca vaccine and plans to roll it out to most of the population. We have also purchased 20 million doses of the Pfizer vaccine and 51 million units of the Novavax jab, which is planned to be used as a subsequent vaccine.

South Africa has now halted its planned rollout of the AstraZeneca vaccine and the clinical trial has been discontinued.

The head of the vaccine and immunisation research group at the Doherty Institute, Terry Nolan, said despite the small sample size in the SA study, the results could prove to be a landmark in understanding how vaccines protect against mutations. There was already some evidence that vaccine efficacy was markedly reduced against the SA variant in phase III trial results from Novavax, in which efficacy dropped to 60 per cent, compared with 95 per cent against the original.

“This is a very significant event,” Professor Nolan said. “There were pointers to it last week, but really now this the first evidence that … it may well be a profound effect on the vaccine efficacy, something that we had hoped wouldn’t occur but looks like it could well have occurred.”

Raina MacIntyre, head of the biosecurity program at the Kirby Institute, said the study’s findings were a “serious concern” for Australia because it was likely that variants of SARS-CoV-2 would become dominant as the year progressed. “We really need to be planning our vaccination strategy accordingly,” Professor MacIntyre said. However, she added that the vaccine could be adapted as new strains emerged.

Professor MacIntyre said it was a “reasonable assumption” that the AstraZeneca vaccine would protect against severe disease and death in the SA variant.

University of Western Australia epidemiologist Zoe Hyde called for Australia to pivot to administering Novavax as a primary vaccine in the wake of the South African study.

“Australia must now reconsider its plan to use the Oxford/AstraZeneca vaccine, and instead use a high-efficacy vaccine like Novavax,” Dr Hyde said.

“It looks like we’re also going to need booster doses to protect us from new strains. Novavax is already working on this, and may even be able to include the South African strain in a combination vaccine. Ongoing booster doses are less feasible with the AstraZeneca vaccine, because people develop immunity to the vector.”

But Nathan Bartlett, an Associate Professor in the School of Biomedical Sciences and Pharmacy at the University of Newcastle, said the AstraZeneca was still likely to be highly effective.

“It’s too early to bin the AstraZeneca vaccine as part of our rollout, especially as the South African variant is not yet prevalent here,” he wrote in an article on The Conversation website.

“Based on Australia’s current circumstances, I think it’s reasonable to say we just need anything that will help reduce the risk of severe disease.”