The Omicron variant was identified in November 2021 and designated a variant of concern due to its large number of mutations. It has over 30 mutations to the spike protein which could impact immune response. While signs and symptoms are similar to other variants, early research suggests Omicron is highly transmissible but less severe. Diagnosis involves testing, imaging, and lab work. Treatment depends on severity but may include antivirals, steroids, oxygen support. Though more transmissible, Omicron appears to be less able to penetrate deep lung tissue and results in lower rates of hospitalization and death compared to Delta.