Experts say there is a path to herd immunity before the end of the year if we make the most of a precious window of opportunity.

Australia has a brilliant window of opportunity to start a vaccine program as soon as possible, says Adjunct Professor Heidi Drummer, program director for disease elimination at Melbournes Burnet Institute.
She welcomes the government’s big decisions this week to accelerate the vaccine roll-out and to tighten controls.
Our healthcare system is intact, only a few people are in hospital with COVID, and we have the capacity and the capability to roll out a vaccine. Other countries are rolling-out against a background of high community transmission in healthcare systems that are overwhelmed.”
She says variants of the virus, not covered by the vaccine, pose a particular risk during this period. The virus randomly generates mutations and, through a process of selection of the fittest, the one that allows it to evade the hosts immune response and replicate wins the day.
This pandemic has marked its first birthday with new mutations that have everyone worried. Just as the first generation of vaccines is being launched, so the virus is changing itself in ways that could potentially outsmart them.
“Our greatest weakness lies in international travellers returning, ” says Drummer. “They represent the entry point for this virus which cleverly jumps barriers. The decision to test travellers and aircrew and to vaccinate everyone involved in managing their arrival will give us another layer of protection. We need an abundance of caution.”
The variant that just tipped Brisbane into lockdown is a flashing red light for the danger ahead. The variant has been identified and contained in Australian quarantine before, but this time it was out in the community.
While some might think the lockdown is the equivalent of squashing an ant with a sledgehammer, it may prove not to be enough.
It’s akin to the swift but prescient action the government took almost a year ago, on February 1 , to close the border with China.
No one really knows if the new vaccines will provide protection against the current strains originating in South Africa and the UK, says Professor Sharon Lewin, director of Melbournes Doherty Institute for Infection and Immunity.
“Its a really important question and is being examined right now. At the moment, its been one step forward and two steps back with this coronavirus around the world.”
We do need to move on with a vaccine because things can change very rapidly.
Professor Sharon Lewin, Doherty Institute
While Australias immediate task is to keep the mutations out of circulation, the Doherty Institute is beginning work on a second-generation vaccine to try to meet future challenges.
This will hopefully be a single dose vaccine that reduces transmission, is manufactured onshore and can be easily delivered, she says.
For Lewin, the urgency for a vaccine in Australia is very different to what is required globally. Abroad, vaccines are being used as a last resort to stop deaths and reduce admissions to hospital.
We’re not in that position currently. But we do need to move on with a vaccine because things can change very rapidly.
As it is not known when or where the next significant mutation might emerge, extreme vigilance is required.
“Australia has a very good system in place to identify mutations quickly. One mutant virus, detected in Melbourne in June, infected 37 people but was rapidly brought under control with lockdown measures in Melbourne at that time.”
The lock down was radical and some experts believe that rather than accelerating approval of the two vaccines, Australia should stick to existing measures.
“There is no information about their long-term effectiveness and safety and no proof they prevent transmission,” says Professor Nikolai Petrovsky, Research Director of Vaxine, which has clinical trials of a COVID-19 vaccine underway in Adelaide.
He’s worried there could be negative public health ramifications, saying one major risk is that they may make symptomatic infections asymptomatic.
“Using them in workers dealing with international arrivals and quarantine could have the paradoxical effect of increasing the risk of further quarantine outbreaks as infected workers pass undetected.”
In contrast, other commentators have criticised Australia for being too conservative, saying epidemiologists have frightened the country, which is not keeping up with advances in logistics, treatment and the science of the pandemic.
But really? Just look around. Theres not one COVID patient in intensive care in the country, less than 30,000 cases have been diagnosed in total and there are less than 300 active cases across the nation.
There have been 909 COVID deaths and certainly, the country has had its shortcomings. One of the biggest was failing to protect the aged sector early enough.
There were security lapses in hotel quarantine, panic that drove people into lockdown without notice and millions were wasted on an app and fast tests that didn’t work.
Our strength has been our respect for science and the political courage to act on it.
Professor Shitij Kapur, Melbourne University’s Medical School
While there was border chaos internally, externally Australian citizens were stranded abroad because the country was unable to bring them home due, in part, to a shortage of quarantine facilities.
Compared to many other countries, Australia had natural strengths for a pandemic. As an island nation it could control its borders and its vast open spaces and low population density helped too. So did the absence of intergenerational living, and our cities with endless suburbs of bungalows conveniently distanced on quarter-acre blocks.
The pandemic also hit in summer, giving the country a few months grace and allowing it to learn from the northern winter.
But could it have done better?
Not much better this time, says Professor Shitij Kapur, dean of Melbourne University’s Medical School. Our strength has been our respect for science and the political courage to act on it, enabled by the financial ability to bail out the lockdowns with Job Keeper and Job Seeker payments.
For next time, however, a greater ability to harness data systems is needed to mount a more organised and cohesive population and personal level response.
The big test ahead is rolling out vaccines as efficiently as Israel has done so far. Although a bigger country, Australia has more time to prepare.
People wait to receive COVID-19 vaccination in Jerusalem. Australia can match Israel’s efficiency while infections remain low.  AP
With war-like logistics and sports-like engagement of community which we have on tap the exercise could be completed by June, subject to availability of vaccines,” says Kapur.
The government’s plan is less ambitious. Its target is to vaccinate half the country by July. Not all citizens will want to line up and vaccination won’t be mandatory.
While keeping the interim period between jabs safe from infection will be an ongoing issue, everyone wants to know if vaccinations will open the skies to international travel?
Even when we are fully vaccinated, we cant assume we will be fully open, ” says Lewin.
People will have a lot more confidence to travel when they’re vaccinated. But returning from international travel will be difficult for some time because we don’t know the effect of the vaccine on infectiousness.
“Perhaps once we get to high vaccination coverage, there will be a shift in policy and quarantine and how we respond to positive cases.
“Rapid tests have some value. They provide an answer straight away but are less sensitive than standard tests and wont solve the issue of quarantine, which is necessary because of the incubation period of this virus.
You can get on a plane with a negative swab, you can get off the plane with the negative swab and can still become positive seven days after leaving the US.
Mutant viruses are just a flight away and 14 days of quarantine is the price people will have to pay to get into Australia for some time.
Although the US Centres for Disease Control has said quarantine could be as short as seven to 10 days, the full 14 remains the safest option.
Lewin says 14 days is based on estimates of the upper bounds of COVID-19s incubation period, which diminishes over time. While most infections emerge early, between 5 and 10 per cent become apparent after 10 days.
So, it’s all about risk and that last 5 to 10 per cent makes a very big difference to us.”
Compared to Hong Kong, Australia’s 14 days seem manageable. Since Christmas Day, everyone arriving in Hong Kong from countries outside China has been mandated to undergo 21-day compulsory hotel quarantine.
In addition, people whove recently been in South Africa are banned and flights from the UK are blocked.
The Asian approach to this pandemic has been tough and has enabled it to outperform Europe, the UK and the US. Australias strategy has been more in sync with its neighbourhood than its security alliances.
In a way, it has been successfully administering Asian medicine with a Western teaspoon.