Omicron’s ability to spread between and cause illness within fully vaccinated Australians will remain unknown for another two to three weeks.
That is when we can expect the results of international tests conducted to determine the new COVID variant’s response to our vaccines and immune systems.
The UK’s chief medical officer, Professor Chris Witty, said last week that the vaccines are still likely to protect people against severe illness and death.
But he said the variant’s high number of mutations meant there was “a reasonable chance … there will be some degree of vaccine escape with this variant”.
In other words, it’s possible the vaccines might be less effective at reducing transmissibility or minimising symptoms.
Here’s what we know so far.
Is Omicron spreading faster than other variants?
The World Health Organisation said preliminary evidence suggests the Omicron variant spreads faster than any current strain of COVID-19 and may have a “growth advantage”. (You can read the full WHO statement here.)
Early data also seems to suggest people are more likely to be reinfected with it than they were with previous strains.
But the WHO’s technical lead on COVID-19, Maria Van Kerkhove, told the Associated Press last week it would take a few weeks “for us to understand what impact this variant has on any potential vaccines”.
The most concerning point is the number of mutations.
Director of the Centre for Epidemic Response and Innovation in South Africa Professor, Tulio de Oliveira, told a government briefing the Omicron variant appears to have a high number of mutations compared to other variants.
Scientists have so far identified more than 30 mutations in the Omicron variant, compared to the 13 to 17 mutations found in the Delta variant.
Some of these mutations affect the virus’s spike proteins, which could make it better at evading our immune systems and spreading between people.
COVID-19 genetic sequencer from the University of Cambridge, Sharon Peacock, told AP the data suggests the variant has mutations “consistent with enhanced transmissibility,” but said that “the significance of many of the mutations is still not known”.
How severe are the symptoms?
Currently, the variant’s characteristics and risk to public health is largely unknown, with the WHO monitoring and tracking the global spread and severity of Omicron.
More will be known when scientists have carried out further testing.
But so far there have been no reports of more severe symptoms.
Dr Angelique Coetzee, the first South African doctor to alert authorities about Omicron, told The Telegraph in the UK that the symptoms were unusual but mild.
No cases had lost their sense of taste or smell, but a six-year-old child had a high pulse rate and young people from different backgrounds were suffering from intense fatigue, she said.
“Their symptoms were so different and so mild from those I had treated before.”
Where did Omicron come from?
South African scientists were the first to identify the Omicron variant after the country experienced a rapid spike in COVID-19 cases in Gauteng, the country’s most populous province.
According to the WHO, the first confirmed infection of the new COVID-19 strain, called B.1.1.529 but later named Omicron, was collected from a specimen on November 9.
It was then reported to the WHO on November 24.
But it remains unclear where the variant emerged.
The average number of new infections reported each day in South Africa has risen by more than 3600 cases over the past three weeks, according to the Reuters COVID-19 tracker.
The country’s health minister, Joe Phaahla, said the variant was linked to an “exponential rise” of cases.
How has Australia responded?
On Saturday, Australia announced flights from South Africa and other at-risk African nations would be suspended for 14 days, with non-Australians who have travelled to those countries now banned from entering the country.
Victoria, South Australia and the ACT brought in similar new rules for all international arrivals amid concern over Omicron.
And SA and New South Wales, where authorities reported two confirmed cases of the Omicron variant on Sunday, have brought in stricter restrictions as well. (More on that in the next section.)
It comes after federal Health Minister Greg Hunt said on Friday he did not think the new strain would immediately affect the country’s plans to reopen.
Mr Hunt said official recommendations would change if required, but there was nothing to be concerned about right now.
On Sunday, he added that the government was closely monitoring the growing severity of the Omicron variant, and had asked deputy chief health officer Paul Kelly to meet state and territory governments on a daily basis.
“The Prime Minister and myself have requested Professor Kelly to continue to meet daily with state and territory counterparts to examine the nature of the variant, all of the international evidence and all of the domestic requirements,” he said.
“And we won’t hesitate if more is needed to take those steps.”
Will states close borders because of Omicron?
NSW Premier Dominic Perrottet insisted the NSW international and state borders would remain open, despite ordering all international arrivals to quarantine at home for 72 hours.
“We can’t be a hermit kingdom on the other side of the world,” he said on Sunday.
“There’s only so much governments can do. The best thing we can do as a people is to get vaccinated, get a booster shot, and that will keep you and your family safe.”
Meanwhile, in SA, people entering the state are once again required to meet requirements including border checks and, in some cases, extended quarantine.
All international travellers and people arriving in SA from high-risk locations in Australia are now required to quarantine for 14 days.
People arriving from lower-risk locations interstate must also have a coronavirus test within the 72 hours before arrival and must show proof of a negative result.
Victorian chief health officer Brett Sutton on Sunday said Omicron was likely to be a “very transmissible variant”.
But he added that “what we do know about Omicron is not enough” to understand the severity of the strain.