Omicron became the dominant variant of Covid in the UK in November last year after it was first detected in South Africa and Hong Kong a month previously - but how can you tell if you have it?
New research could help you identify the difference between Omicron and a cold, reports the Mirror.
Research from Norway identified how Omicron affects the fully vaccinated, following a study interviewing 111 of 117 guests at a party on 26 November 2021.
READ MORE: Edinburgh mum left in wheelchair after 'shivers' on walk turned out to be sepsis
The findings published in infectious disease and epidemiology journal Eurosurveillance, discovered that there were eight main symptoms experienced by the group of fully vaccinated partygoers.
These included a cough, runny nose, sore throat, fatigue, headache, muscle pain, sneezing and pain.
The most common among those who were vaccinated were coughing, fatigue and a runny nose, with sneezing and a fever the least reported.
Nausea is also a symptom of the Omicron variant, in vaccinated people, according to public health experts.
Omicron symptoms:
- Cough
- Runny nose
- Sore throat
- Fatigue
- Headache
- Muscle pain
- Sneezing
- Pain
There was an Omicron outbreak at the party and 89 per cent of participants had two coronavirus jabs.
Out of those interviewed, 66 had confirmed cases of Covid-19 and there were 15 potential cases.
Vaccinations protect against the most serious risks of coronavirus, it is still possible to contract Covid, despite having had both vaccinations and a booster.
Vaccination also makes it more likely that symptoms will be mild, so it can be difficult to distinguish between coronavirus and a common cold.
According to Professor Tim Spector, from the ZOE Symptom Study App, approximately 50 per cent of "new colds currently are, in fact, Covid".
Sign up for Edinburgh Live newsletters for more headlines straight to your inbox
The two symptoms which could signal an early warning sign of Omicron are fatigue and dizziness/fainting.
Speaking to Good Morning Britain, Dr Angelique Coetzee, a private practitioner and chair of the South Africa Medical Association, said that fatigue was one of the main symptoms of Omicron to emerge when the variant first appeared in South Africa.
A Web MD poll discovered that 40 per cent of women said they struggled with fatigue because of Covid, in comparison to a third of men.
The correlation between fainting spells and Omicron was identified by a new report from Germany; the German newspaper Arztezeitung said doctors could see a "clear connection" between the infection and fainting spells.