Health Minister Greg Hunt has reassured Australians that the AstraZeneca vaccine still has strong results against serious illness and death from the Omicron COVID variant, despite a British study warning it has “no protective effect” against the virulent new strain.

It comes as the federal government prepares to reopen international borders to foreign workers and students on Wednesday, following a two-week pause on the plan as the Omicron variant emerged.

“The advice continues to be that all of our vaccines provide strong, clear protection against serious illness, hospitalisation and loss of life. That is a very important point,” Mr Hunt said on Monday.

“The evidence on transmissibility, that’s under consideration.”

Health Minister Greg Hunt. Photo: Getty

Britain’s Health Security Agency published a study on Saturday that examined the effectiveness of the Pfizer and AstraZeneca vaccines against the Omicron variant. The pre-print paper, which has not yet been peer-reviewed but was published on the British government’s website, raised concerns that the vaccines were less effective at stopping transmission of Omicron than previous strains such as Delta.

Initial studies indicate Omicron causes a milder illness and less severe symptoms than Delta. However, it appears to be more transmissible than previous strains. Britain is battling a surge of Omicron, described as a “tidal wave” by Prime Minister Boris Johnson.

The British study of 581 people found that, for people immunised with two doses of AstraZeneca, “there was no protective effect of vaccination against symptomatic disease with Omicron from 15 weeks after the second dose”.

For those receiving Pfizer, the vaccine’s effectiveness at stopping Omicron transmission was pegged at between 34 and 37 per cent, from 15 weeks after a second dose.

Fifteen weeks is just short of four months. Britain is offering COVID booster shots just three months after a second dose.

On Sunday, the Australian government announced boosters would be available five months after a second dose, revised down from six months.

The same study found that a Pfizer booster for people who’d received two AstraZeneca jabs raised vaccine effectiveness to 71.4 per cent as little as two weeks after the shot. For people receiving a Pfizer booster after two primary Pfizer doses, that effectiveness was 75.5 per cent.

Mr Hunt, who had two shots of AstraZeneca before a Moderna booster on Sunday, said he and Australia’s top health officials were aware of the study and considering its implications.

Tweet from @GregHuntMP

“They have considered all of the international evidence and their determination was to bring forward the boosters by one month and they have had extensive reviews of the whole range of international evidence,” he said.

“We will continue to follow the medical evidence and if there were additional advice, we will follow that.”

Mr Hunt said the Australian Technical Advisory Group on Immunisation had discussed the issue “at length and in great depth”. He said Omicron was believed to be more transmissible and less severe, but stressed current vaccines still have strong benefits against serious illness, hospitalisation and death.

“More evidence is required. It’s too early to call out definitively but the
evidence is growing that it may well be more transmissible on the one hand, but [vaccines have] strong protection against serious illness and hospitalisation and loss of life on the other hand,” Mr Hunt said.

The government is encouraging Australians to get a booster if they are more than five months on from their second vaccine dose. Pfizer and Moderna are available, with nearly 700,000 people as of Sunday having already received a third shot.

“There are over 8500 primary care sites, over 9000 sites all up with state clinics. If you’re due for your booster, whether it’s Moderna, whether it’s Pfizer, there’s an opportunity everywhere,” Mr Hunt said on Sunday.

Also on Monday, he confirmed Australia’s borders would reopen to international workers and students on Wednesday, as planned. That reopening, initially flagged for December 1, was delayed two weeks over the emergence of the Omicron variant.

Travel restrictions will also ease for those coming from Japan and South Korea, as Prime Minister Scott Morrison reaffirmed at a press conference alongside visiting Korean President Moon Jae-In.

“The borders will be reopened both to Korea and to Japan and for skilled migration and for students as we conclude the pause that we announced several weeks ago,” Mr Morrison said in Canberra.

“This is made possible because Korea and Australia have both shared a COVID-19 experience … we are two countries that have had one of the lowest death rates from COVID in the world. We have both got one of the strongest economies.”