The omicron variant could be settling in the gut rather than the nose, Professor Tim Spector, from the ZOE Covid Symptom Study, told the Sun Online, Report informs.
This means, when people are infected and experiencing gut symptoms like an upset stomach they will test negative - as there won't be traces of Omicron in the nose or mouth. Nausea, abdominal pain, vomiting, loss of appetite and diarrhoea could all be signs of Covid.
Experts have however said that while nausea or vomiting might not be key signs of the virus, they could sit alongside other symptoms.
Studies have shown that people who have Covid-19 can sometimes experience gastrointestinal symptoms.
The omicron variant, or B.1.1.529, was found in Botswana and South Africa in November. According to experts, those who previously had COVID and those who got vaccinated can become infected with it. The new variant has already been identified in more than 140 countries, including Azerbaijan.