News of the Omicron variant of the coronavirus has spread rapidly around the world after it was first identified in South Africa earlier this week.
With cases of the variant now confirmed in nearby neighbours Britain, the Netherlands, Germany, Belgium and Italy, here is what we know about how the variant could impact Ireland.
Why are officials concerned?
The Omicron variant is causing concern worldwide because it has over 30 mutations in the part of the virus that current vaccines target. This might help it spread more easily, or even evade antibodies from prior infection or vaccination.
The World Health Organisation on Friday classified Omicron as a "variant of concern," noting it may be more transmissible and have an increased re-infection risk. It is suspected of driving a recent rise in cases in South Africa.
However, experts are stressing they do not yet know enough about the variant to be sure of the consequences of its mutations. The Delta variant remains dominant worldwide, and it is not yet clear whether Omicron will be able to displace it.
Is the variant already in Ireland?
No case of the variant has been confirmed in Ireland to date.
Minister Eamon Ryan on Sunday said the variant is “across Europe, it seems” and while Ireland is doing “a lot of testing,” it has not yet picked it up.
However, one health expert has said the Omicron variant is “probably here already” but has not been identified yet due to a lack of genetic sequencing.
Anthony Staines, Professor of Health Systems at Dublin City University (DCU), said Ireland sequences around just 10 per cent of its cases, meaning the variant may be going unnoticed at present.
What is being done to prevent it taking root here?
The National Public Health Emergency Team (Nphet) are meeting throughout the weekend to monitor the impact of Omicron, considering further measures to "mitigate" its arrival in Ireland.
Initial measures are already in place, with Irish residents returning home from southern Africa now required to undergo “strict” home quarantine and PCR testing, regardless of their vaccination, recovery or test status.
While Ireland currently has no direct flights from any of the countries affected, the State had aligned with the EU recommendation to apply an “emergency brake” on travel to or from Botswana, Eswatini, Lesotho, Mozambique, Namibia, South Africa and Zimbabwe.
The Department of Justice is also updating visa requirements for these countries and arranging increased Border Management Unit spot-checking of passengers on arrival.
Work is also underway to prepare legislation which would facilitate the reintroduction of the mandatory hotel quarantine system, with it to be discussed by the Cabinet on Tuesday.
So will our vaccines work?
The biggest question surrounding Omicron is whether protection from Covid vaccines will hold up, and if people previously infected will be immune from infection.
Although it is too early to know how effective vaccines will be against the variant, several health experts have said there is currently no evidence to suggest that vaccines will be rendered ineffective.
Dr Cillian de Gascun, a member of the National Public Health Emergency Team (Nphet), said there is no reason to believe “at this stage” that vaccines or anti-viral medicines will not work against the new variant of the virus.
Another scientist behind the Oxford/AstraZeneca Covid-19 vaccine, Professor Andrew Pollard, has expressed optimism “from a speculative point of view” that existing vaccines will continue to be effective against severe disease with the variant.
And what if the vaccines don’t provide much protection?
Even then, we’re not necessarily back to square one.
Numerous pharmaceutical firms have said they are already working to adapt their vaccines in light of the emergence of Omicron.
Could Omicron make people sicker?
Again, it is too early to tell if Omicron will cause more or less severe Covid-19 compared to other coronavirus strains.
One doctor who discovered the new variant, chair of the South African Medical Association Dr Angelique Coetzee, said doctors in South Africa are seeing “extremely mild” cases.
South Africa’s health minister Joe Phaahla said “it is still too early at this stage” to say how unwell the variant is making people, but he has heard anecdotally that cases have been “mild” and mostly in the young, for whom vaccination rates are relatively low in South Africa.
“Some of what I’ve read from some of our clinicians has been that thus far they have not witnessed severe illness. Part of it may be because the majority of those who are positive are young people,” he said. However, he stressed these anecdotal reports are “not proper research”.
When will we know the answers to all these unknowns?
Scientists say it could be several more weeks before they can define the type of disease caused by the variant, determine how contagious it is and identify how far it has already spread.
What can I do to protect myself in the meantime?
Experts around the world have said vaccination should remain a priority despite questions about effectiveness against Omicron, because it is likely that the jabs will still remain protective to a certain extent.
Everyone should also continue to wear masks, avoid crowds, ventilate rooms, and wash hands - tools that experts say will work against any variant.