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Australia: Omicron joins an alphabet of COVID-19 variants — here’s how it differs to those that came before

Fears new Covid super-variant Omicron ALREADY is already in Australia

  Fears new Covid super-variant Omicron ALREADY is already in Australia Health Minister Greg Hunt on Saturday announced Australia would be joining Europe and the US in closing its borders to nine southern African countries to stop the new variant from entering the country. There are though 20 returned travellers quarantining in the Northern Territory who were repatriated from South Africa last week - one of whom has tested positive to Covid.Health officials in the Northern Territory are expected to confirm whether or not the infected case has the hyper-virulent new variant later on Saturday evening.

Scientists are working quickly to determine the severity of the Omicron variant, after it was designated a "variant of concern" by the World Health Organization (WHO) this weekend.

At present, it is unclear whether Omicron is more transmissible than Delta, which prompted lockdowns across Australia's east coast earlier this year, or if it will impact vaccine immunity.

It's still early days, but it's possible Omicron could go the way of other "transient" variants identified by WHO that subsided without widespread impacts.

So far, 11 variants have been named by the WHO.

The WHO uses three classifications to categorise variants: variants of concern (VOC), variants of interest (VOI), and variants under monitoring (VUM).

Is it inevitable the Omicron variant of COVID-19 will spread like Delta?

  Is it inevitable the Omicron variant of COVID-19 will spread like Delta? The emergence of the Omicron variant of coronavirus shows Africa needs greater access to vaccines, experts say. There are also warnings we shouldn't give up masks, social distancing or contact tracing in Australia.The federal government on Saturday announced that non-Australian citizens who have been in nine countries in southern Africa where Omicron has been detected are barred from entering Australia.

Five are currently considered variants of concern and two are variants of interest. The remaining six are either being monitored or are no longer considered a threat.

The most serious category, variants of concern like Delta and Omicron, refers to strains that increase transmissibility or cause a detrimental change in COVID-19 epidemiology, increase virulence or change clinical disease presentation, or decrease the effectiveness of public health measures or available diagnostics, vaccines, or therapeutics.

Not all variants are stayers

When it comes to viruses, it's survival of the fittest.

When a highly transmissible variant like Delta comes along, it is able to reach more people and infect them first — leaving other variants with lower transmissibility nowhere to go.

PM 'fully supports' action by NSW and VIC with Omicron fears growing

  PM 'fully supports' action by NSW and VIC with Omicron fears growing The Prime Minister Scott Morrison has said he 'fully supports' the action taken by New South Wales and Victoria amid growing fears over the super-contagious Omicron strain of Covid-19. But Dr Paul Griffin, Director of Infectious Diseases at Mater Health in Brisbane, said it was still too early to judge the risks of Omicron.'I don't think we're back to square one. I mean, I think a lot of us thought this is what this virus is going to keep doing, going to keep evolving and we are going to keep finding new variants,' he told ABC.

It's this same principle that has some experts hoping Omicron could actually be a good thing. If Omicron is, in fact, more transmissible than Delta but with less severe symptoms, as some early evidence suggests, it could eventually become the dominant strain.

"If Omicron ends up being more infectious, but less severe in all age groups, vulnerable populations and vaccinated populations, then that wouldn't necessarily be a bad situation," says Associate Professor Sanjaya Senanayake, an infectious disease specialist at the Australian National University.

"Of course, the risk again is that if it takes hold in unvaccinated regions around the world and generates lots of infections ... then that would be a risk for a new, more dangerous variant to appear."

If you're starting to lose track of where we are at in the Greek alphabet, here's a run-down of the COVID-19 variants identified so far and how they differ from each other.

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  TWO confirmed cases of fears Omicron Covid strain are found in Sydney NSW Health announced on Sunday urgent genomic testing had confirmed two overseas travellers have the South African variant of the virus.NSW Health confirmed on Sunday urgent genomic testing found the two travellers who touched down in Sydney on Saturday night have the new strain.

Omicron — a variant of concern

What makes Omicron notable, according to Tony Cunningham, the co-director of the Centre for Virus Research at the Westmead Institute, is the high number of mutations in its spike protein. "The number of mutations are greater than we've seen in any one variant before," he says.

In fact, it appears that Omicron has double the amount of mutations that Delta has, compared to the original virus from Wuhan. The more mutations a variant has, the more possibilities there are for the virus to evade antibodies from vaccines and previous COVID-19 infections.

Cassandra Berry, a professor of viral immunology at Murdoch University, says we are also "seeing more people being infected [with Omicron] than we would predict".

But it's still unclear whether Omicron is actually more infectious than Delta. "You need to have a virus that multiplies to a high degree in the nose to be able to outcompete Delta, and we don't know if it will do that yet," Professor Cunningham says.

He adds that it was unusual for Omicron, which was first detected in South Africa last week, to be christened a variant of concern when it has only been detected in a handful of countries outside southern Africa. The early concern is likely due to the high number of mutations, he says.

Dominic Perrottet vows NSW will stay open despite Omicron variant

  Dominic Perrottet vows NSW will stay open despite Omicron variant NSW Health confirmed on Sunday two travellers who touched down in Sydney on Saturday night have the new South African Covid variant, Omicron, which is feared to be more transmissible than Delta.NSW Health confirmed on Sunday urgent genomic testing found two travellers who touched down in Sydney from southern Africa on Saturday night have the new strain.

According to the WHO, preliminary evidence suggests there may be an increased risk of reinfection with Omicron compared to other variants of concern, meaning people who have previously had COVID-19 could more easily catch the virus again.

To illustrate, Professor Berry describes the spike protein and antibodies as a lock and key. "The mutation is changing its shape on the tip of the spike, and the antibodies won't bind to its shape," she says. "It's like the key won't fit into the lock anymore."

Studies looking at the impact of Omicron on vaccine efficacy are currently underway. In the meantime, scientists and health authorities have urged all Australians to get their COVID-19 booster shot as soon as they are eligible.

"Getting your antibodies sustained is really important," Professor Berry says. "Any protection is better than none."

Delta — a variant of concern

Currently the dominant COVID-19 variant worldwide, Delta is at least two times more contagious than previous strains.

One person with Delta — which was first detected in India in October 2020 — will spread the virus to between five and eight people. By comparison, someone with the original Wuhan strain of the virus would likely pass it on to 2.5 people.

As a result, the variant quickly snaked its way across the world, forcing many countries to rethink their pandemic response. It was designated a variant of concern in May.

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In Australia, the transmissibility of the variant meant contract tracing, border closures, and targeted lockdowns were no longer able to completely eliminate outbreaks.

"If you're running a relay race, ultimately it's a question of who gets to the finish line first and Delta is able to do that," Professor Cunningham says of Delta's spread. "It's a competition for space."

The symptoms associated with Delta were also different to what we had come to expect from the original virus strain. Where previously fever, a persistent cough, and loss of taste or smell were the most common symptoms, Delta is more likely to cause headaches, a sore throat, runny nose, and then fever.

Alpha — a variant of concern

The first variant to be given a name, Alpha is still considered a variant of concern by the WHO. It was first documented in the United Kingdom in September last year and has since spread to more than 170 nations.

It is estimated to be about 50 per cent more transmissible than the original virus, and was the dominant strain in the United Kingdom before being overtaken by Delta.

The variant was also identified as the source of a cluster of cases in Brisbane earlier this year.

Beta — a variant of concern

The oldest variant of concern, Beta was first detected in South Africa in May last year — just months after the pandemic took hold.

Beta didn't "go very far", Professor Cunningham says, but "the concern was it was more resistant to vaccines than Alpha".

For example, the effectiveness of the Novavax vaccine dropped from 90 per cent to 60 per cent against Beta, he says.

Omicron 3 times more likely to cause reinfection than previous COVID variants: researchers

  Omicron 3 times more likely to cause reinfection than previous COVID variants: researchers South African scientists say the risk of reinfection from the omicron COVID-19 variant is at least three times higher than for any previous variant. In the preliminary study, researchers looked at approximately 2.8 million positive coronavirus infections between March 2020 and Nov. 27, 2021, and 35,670 suspected reinfections were identified. From this retrospective analysis, the group said increases in primary infection were observed following the introduction of both the beta and delta variants, but no corresponding increase was observed in the reinfection hazard.

But eventually, it fell victim to Delta. "Delta spreads faster than Beta, so Delta gets to the vulnerable people, the unvaccinated people, faster than Beta does, so Beta has nowhere to go," Professor Cunningham says. "So it's really declined."

Gamma — a variant of concern

Gamma was first detected in late 2020 in Brazil and was designated a virus of concern in January the following year. It was first publicly reported after four Brazilian travellers tested positive for the virus in Japan.

Like many of the variants of concern, Gamma has mutations that help it evade antibodies. It's possible the strain led to a surge in cases in the Brazilian city of Manaus, where it was estimated 75 per cent of the population had previously contracted COVID-19.

Lambda — a variant of interest

There was lots of attention on Lambda when it was first named a variant of interest in June, after first being detected in Peru at the end of last year.

Early reports suggested the variant could be fast-spreading and difficult to tackle with vaccines. In April and May, it accounted for more than 80 per cent of COVID-19 cases in Peru and was also prevalent in Chile, Argentina and Ecuador.

It also made its way to Australia, by way of an international traveller in hotel quarantine, but failed to take hold in the community. "The reason why is Delta simply outcompeted it in Sydney and Melbourne," Professor Cunningham says.

It currently accounts for less than 0.5 per cent of cases worldwide.

Mu — a variant of interest

First detected in Colombia at the start of this year, the WHO designated Mu a variant of interest in August. It has since been found in at least 50 countries, but represents less than 0.5 per cent of cases worldwide.

Its classification as a variant of interest means it has mutations that are predicted or known to affect virus characteristics, such as transmissibility, severity, and immunity, and is responsible for significant community transmission in multiple countries.

COVID-19 Omicron variant: New York, tri-state area confirm more cases as hospitals strain from delta surge

  COVID-19 Omicron variant: New York, tri-state area confirm more cases as hospitals strain from delta surge The tri-state area has counted just under a dozen cases of the COVID-19 omicron variant as hospitals continue to feel the strain from the delta surge. Health officials have confirmed cases of the omicron variant in over a dozen states, including New York, New Jersey, and Connecticut. New York City, where a Minnesota case of omicron originated, alone has confirmed seven cases.

At the time of its designation, the WHO said Mu had a "constellation of mutations that indicate potential properties of immune escape". This means it has the potential to get around vaccine and natural immunity.

Kappa, Iota, Eta — variants under monitoring, formerly of interest

The WHO defines variants under monitoring as those with genetic changes that are suspected to affect virus characteristics, but evidence of epidemiological impact is still unclear.

Three former variants of interest currently fall under this category: Kappa, first documented in India in October 2020, Iota, detected in the United States in November 2020, and Eta, found in multiple countries in December 2020.

Kappa, which developed from the same strain as Delta, triggered a lockdown in Victoria earlier this year after it escaped hotel quarantine in South Australia.

Epsilon, Zeta, Theta — formerly monitored variants

These little-known variants were once on the WHO's radar, but have since been reclassified because they either stopped circulating at significant levels, failed to have an effect on the epidemiological situation, or evidence emerged that they were unlikely to be of concern.

What about Nu and Xi?

Eagle-eyed Greek scholars may have noticed two letters missing from the list of variant names. Nu and Xi, which come before Omicron in the Greek alphabet, were not forgotten by mistake.

According to a WHO spokesperson, Nu was skipped because "it is too easily confounded with 'new'."

Meanwhile, the organisation opted against using Xi as it is a common surname. "WHO best practices for naming new diseases ... suggest avoiding 'causing offence to any cultural, social, national, regional, professional or ethnic groups'," they said.

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COVID-19 Omicron variant: New York, tri-state area confirm more cases as hospitals strain from delta surge .
The tri-state area has counted just under a dozen cases of the COVID-19 omicron variant as hospitals continue to feel the strain from the delta surge. Health officials have confirmed cases of the omicron variant in over a dozen states, including New York, New Jersey, and Connecticut. New York City, where a Minnesota case of omicron originated, alone has confirmed seven cases.

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