THE emergence of the Omicron variant is the "most challenging development of the pandemic for quite some time", Nicola Sturgeon has said. 

The First Minister was speaking during an emergency briefing convened after six cases of the variant were detected in Scotland, in addition to three already confirmed in England.

Four were identified in Lanarkshire and two in Greater Glasgow and Clyde. 

Some of the people identified have no travel history or known contact with someone recently returned from overseas, indicating community transmissions.

READ MORE: Where has the Omicron variant been found in Scotland?

However, Ms Sturgeon said there was nothing to suggest community transmission is "sustained or widespread". 

All six individuals identified as infected with Omicron are isolating, but none have required hospital treatment to date. 

Contact tracing is taking place to establish the origin of the virus and find anyone else they have come into contact with in recent weeks.

In particular, surveillance is pinpointing any cases with a marker known as an S-gene dropout, a characteristic found in the Omicron variant but not in the dominant Delta strain which makes up some 99 per cent of UK cases. 

Public Health Scotland has been re-analysing positive PCR tests retrospectively in order to identify S-gene dropout cases in recent weeks, and putting these forward for genomic sequencing. 

To date, this indicates that the first known case of Omicron was detected in Scotland on November 23. 

Scotland's chief medical officer Dr Gregor Smith said that other samples were still being processed but that there were "not significant numbers" of S-gene dropout cases, and that some had "already being discounted" as not being Omicron. 

Dr Smith added that surveillance shows S-gene drop out cases "beginning to appear again" in Scotland more frequently from November 16 onwards.

Ms Sturgeon added: "We're not seeing hundreds and hundreds of S-gene dropout cases."

All close contacts of suspected Omicron cases will be advised to self-isolate for 10 days, regardless of their vaccination status.

READ MORE: Omicron cases in Scotland are 'wake-up call' as community transmission likely

The First Minister said she could not disclose the vaccination status of any of the six confirmed Omicron cases in Scotland due to patient confidentiality.

However, the Herald is aware that two cases so far identified in England involved patients recently returned from South Africa, one of whom was fully vaccinated and a second who was fully vaccinated and had also previously recovered from an infection caused by the Delta variant.

Dr Smith said there is currently no evidence to directly link any of the identified cases in Scotland to the recent COP26 climate summit in Glasgow.

Omicron was first reported in South Africa, but cases have been detected in countries across the world, including Australia, Germany, Israel and Hong Kong.

Ten countries in southern Africa - South Africa, Namibia, Zimbabwe, Botswana, Lesotho, Eswatini, Malawi, Mozambique, Zambia, and Angola - have been added to the travel "red list", meaning that non-UK nationals are banned from entry and UK nationals returning from these countries must enter 10-day hotel quarantine.

From 4am tomorrow, all overseas travellers arriving into the UK will need to take a PCR test on day two and self-isolate pending a negative result. 

However, Ms Sturgeon and her Welsh counterpart, Mark Drakeford, have written to the Prime Minister requesting that these rules are tightened to require all international travellers to self-isolate for longer - taking tests on day two and day eight after arrival, and only ending their home quarantine if the second test is negative. 

The First Minister said this was necessary to "reduce the risk from imported cases" given the incubation period for the virus, which averages around five days. 

Ms Sturgeon stressed that there is a "huge amount" that scientists still do not know in relation to the new variant, including whether it is more transmissible than Delta or whether it will make existing vaccines less effective. 

Omicron has been spreading rapidly in South Africa and has around 50 mutations in total, including 30 on the spike protein - twice as many as Delta - compared to the original Wuhan strain on which Covid vaccines are based. 

Ms Sturgeon said there was currently no evidence to show that the new variant causes significantly different symptoms or more severe disease, but stressed that we should "treat it seriously and act on a precautionary basis". 

"There is no doubt that this presents, potentially, the most challenging development in the pandemic for quite some time," she said. 

The First Minister urged the public to "step up" compliance with existing public health measures including hand-washing and wearing face masks in shops, hospitality and on public transport; to take up vaccines and boosters if eligible; and to work from home wherever possible. 

From today, she said working from home should be "maximised" by employers and that everyone should take a lateral flow test before going Christmas shopping or socialising with others, including going to pubs, restaurants or to someone else's home.

"If we all do that then we're going to have a massive downward impact on transmission, because we'll be cutting off any opportunities for the virus to spread," said Ms Sturgeon.

Surge testing is also being deployed in areas where Omicron has been detected so far to help to identify any other cases. 

The Joint Committee on Vaccination and Immunisation will issue a statement later today which is expected to extend eligibility for booster jags to all adults and to cut the timescale from six months to five months from a second Covid inoculation. 

Ms Sturgeon said the Scottish Government was not introducing any additional restrictions at present or asking anyone to change their plans, only to "significantly step up compliance" with the existing measures. 

She said she hoped that this would be enough to contain the virus and enable Scots to enjoy a "more normal" Christmas this year, but could not rule out going further in the days and weeks ahead.

"I think it's foolish to rule things out categorically when we're trying to deal with a virus, and equally it's sensible to keep our minds open.

"I'm confident that the measures we're asking everyone to comply with right now have a downward push on transmission.

"We don't know yet what the transmissibility of this new variant is so we can't say for certain that the current protections in place will be sufficient against it. But we do know they'll have an impact."

Asked whether the Scottish Government would escalate restrictions, for example introducing a circuit breaker lockdown ahead of Christmas, if the Treasury provided an assurance of funding for furlough and business support grants - something she and Mark Drakeford have requested - the First Minister insisted that she does not want to impose tougher curbs.  

It comes as hospitality trade bodies were today called to an emergency meeting with Finance Secretary Kate Forbes and Scotland's National Clinical Director, Jason Leitch.

Ms Sturgeon said: "I don't want to introduce any more protections and I really hope we don't have to do that.

"It is about making sure we have the assurance that should that prove necessary we're not stopped from doing what is necessary in a public health sense by the lack of financial support. 

"If we get an assurance around what Mark Drakeford and I are asking for today I still hope we will never have to activate that because the public health circumstances will ensure that additional protections are not necessary."