Earlier booster jabs may delay Omicron progress

Health experts want booster shots to be given earlier as cases of the “concerning” ­Omicron variant are confirmed in Australia.

Virus specialist Professor Tony Blakely said bringing forward plans for a third vaccine dose could protect against the new strain if it appeared to spread more quickly.

“The waning of Pfizer and AstraZeneca is quite profound by six months, so you can make the case to bring it forward to five months,” he said.

Two passengers from South Africa who arrived in Sydney on Saturday night have tested positive for the Omicron strain, which has officials working around the clock to understand its high trans­missibility and what it means for vaccine efficacy.

It comes as another person, suspected of being a third ­Omicron case, came to Victoria from New South Wales on Thursday.

The person has tested positive to Covid and since returned to NSW.

At least 40 travellers who have landed in Australia from nine African countries of ­concern in recent weeks are in Victoria and will have to isolate for 14 days.

Prime Minister Scott Morrison on Sunday backed Victoria’s decision to impose a 72-hour isolation period for all international arrivals as “sensible”.

“This is a fast-moving issue, but we will continue, as we always have, sensible, ­balanced, guided by the best possible medical evidence and medical expert advice,” Mr Morrison said.

But he also called for calm, saying that Australia’s goal was to “remain safely open” as fears mount over border closures in the lead-up to Christmas holidays.

Epidemiologists told the Herald Sun that existing vaccines might need to be tweaked and new vaccines delivered if the Covid-19 Omicron variant spread rapidly in Australia.

Professor Blakely said the next few weeks would be ­crucial in understanding how resistant the variant was to current vaccines.

“It’s quite likely that this will precipitate new branches of vaccine development, there’s just so many mutations on this virus it would seem most likely we will need new vaccines,” he said.

Professor Blakely said if the variant was more infectious, he hoped it would be less deadly, which would replace Delta as the dominant strain and be “easier” to live with.

“Whether that’s the case or not, we won’t know for a while,” he said.

“The worst-case scenario is it’s more infectious, it’s more virulent and it’s resistant to current vaccines.”

A third booster dose of ­current vaccines could also be brought forward to combat waning immunity and better prepare for next winter.

More than 1.5 million Australians are due for booster shots by Christmas Day, mainly frontline workers and people in high-risk groups, including those with a disability. By January, 2.5 million will need to book their booster, before it climbs to 3.25 million in February and four million in both March and April.

Australia will be able to order vaccines being developed to tackle new Covid strains, such as the concerning Omicron variant, under its ­existing deals with Pfizer and Moderna.

A federal Health Department spokesman has confirmed that the federal government’s existing contracts with Pfizer and Moderna include “purchasing vaccines developed which may be effective against variants”.

He said the government was in “regular contact” with the pharmaceutical companies about vaccine supply and new variants of concern.

BioNTech, who developed a vaccine with Pfizer, has claimed it could produce and ship a modified vaccine that could combat Omicron within 100 days.

Co-chair of Australia’s ­expert immunisation panel, Professor Allen Cheng, said a new variant vaccine would have to go through an approvals process.

“I suspect that the hurdles to getting vaccines into arms would be less about doing the studies and the regulatory side than actually having the supply,” Professor Cheng said.

But Professor Cheng said that it was premature to know if ­reducing the six-month interval between second shot and booster would provide greater protection because it was untested.

“We need more data to know if that is going to be a successful strategy,” he said.

Former World Health Organisation epidemiologist Adrian Esterman said current vaccines would likely give “some protection” against Omicron, but nowhere near as much compared with the ­original strain.

He said new vaccine technologies had made it easier to modify existing formulas.

He said the Omicron variant highlighted the need for purpose-built quarantine hubs such as Mickleham to be prioritised.

Victoria’s chief health officer Brett Sutton said the variant would be “impossible to keep out” and would likely become the new dominant strain.

Professor Sutton reassured Victorians that they were “not back at square one”, adding travel restrictions would “buy time” while authorities determined the next steps.

Professor Sutton said the Omicron variant was likely to be in dozens of countries and was a consequence of vaccination coverage in Africa being “in single figures”.

Health Minister Martin Foley confirmed international flights carrying people who had recently been in southern Africa had arrived from other countries. But he refused to be drawn on whether Victoria should stop accepting all international arrivals, saying that it was “a matter for the Commonwealth”.