While the origin of the Omicron variant is still unclear, World Health Organization reports indicate that the Omicron variant spreads faster than the Delta variant and, as of January 6, 2022, has been identified in 149 countries.

While it has a high transmissibility, the symptoms and virulence of Omicron appear to be lesser than previous variants. Omicron patients commonly reported a scratchy throat first, followed by nasal congestion, dry cough, and body aches. Many patients started with a dry, scratchy throat that caused sharp pain when they swallowed. Symptoms from previous variants have dwindled, such as loss of smell and taste, fevers, and coughing. In December 2021, Hong Kong University researchers discovered that Omicron replicated 70 times faster in the bronchi, part of the respiratory system, than Delta. While the Moderna, Pfizer, Johnson & Johnson, and AstraZeneca vaccines appear to protect against the worst symptoms, those who are not vaccinated are at a high risk of serious illness. In general, Omicron does appear to be less harmful than Delta, but it is not mild. Omicron is not only capable of breakthrough cases but also has high asymptomatic transmission rates.

Omicron is more contagious than all other previous versions of COVID-19. Omicron is also harder to detect, and the virus has moved from the lungs and into the nasal cavities and throat. Despite the high level of contagiousness, the virus has become less lethal, specifically to those with respiratory issues and underlying health conditions. Symptoms have changed, being more feverish with a sore throat, and old symptoms such as loss of taste and smell have diminished. Omicron is becoming less deadly, but it is unclear what this means for the future of the virus and the world.