Centers for Disease Control and Prevention (CDC) added a new designation for variants: variant being monitored (VBM). This refers to variants for which data indicate a potential or clear impact on approved or authorized medical countermeasures or variants associated with more severe disease or increased transmission rates. However, these variants are either no longer detected or are circulating at very low levels in the United States; therefore, they do not pose a significant and imminent risk to public health in the United States. The Omicron (B.1.1.529) variant was designated a VOC in November 2021 and rapidly became the dominant variant across the globe. More recently, the Omicron subvariants BA.1, BA.1.1, and BA.2 have emerged. The Omicron VOC is more transmissible than other variants and is not susceptible to some of the anti-SARS-CoV-2 mAbs that have been developed for treatment and prevention.20,21,24 The Omicron VOC has surpassed Delta (B.1.617.2) as the dominant variant in the United States; the Delta variant was first identified in India and was the dominant variant in July 2021. Earlier variants include the Alpha (B.1.1.7) variant, which was first seen in the United Kingdom and has been shown to be highly infectious and possibly more virulent than previously reported variants;25- 27 the Beta (B.1.351) variant, which was originally identified in South Africa; and the Gamma (P.1) variant, which was identified in Manaus, Brazil. The Beta and Gamma variants demonstrated reduced susceptibility to select anti-SARS-CoV-2 mAbs used for treatment and prevention. Although the Alpha, Beta, and Gamma variants were previously designated as VOCs, they have largely disappeared worldwide. For a detailed discussion on the susceptibility of certain VOCs, VOIs, and VBMs to available anti-SARS-CoV-2 mAbs, please see Anti-SARS-CoV-2 Monoclonal Antibodies. Data on the emergence, transmission, and clinical relevance of these new variants are rapidly evolving; this is especially true for research on how variants might affect transmission rates, disease progression, vaccine development, and the efficacy of current therapeutics. Because the research on variants is moving quickly and the classification of the different variants may change over time, websites such as the CDC COVID Data Tracker and CoVariants.org provide regular updates on the data for SARS-CoV-2 variants. The COVID-19 Treatment Guidelines Panel reviews emerging data on these variants, paying particular attention to research on the impacts of these variants on testing, prevention, and treatment. Clinical Presentation The estimated incubation period for COVID-19 is up to 14 days from the time of exposure, with a median incubation period of 4 to 5 days.6,28,29 The spectrum of illness can range from asymptomatic infection to severe pneumonia with acute respiratory distress syndrome and death. Among 72,314 people with COVID-19 in China, 81% of cases were reported to be mild (defined in this study as no pneumonia or mild pneumonia), 14% were severe (defined as dyspnea, respiratory frequency ≥30 breaths/min, oxygen saturation ≤93%, a ratio of arterial partial pressure of oxygen to fraction of inspired oxygen [PaO2 /FiO2 ] 50% within 24 to 48 hours), and 5% were critical (defined as respiratory failure, septic shock, and/or multiple organ dysfunction syndrome or failure).30 In a report on more than 370,000 confirmed COVID-19 cases with reported symptoms in the United States, 70% of patients experienced fever, cough, or shortness of breath; 36% had muscle aches; and 34% reported headaches.2 Other reported symptoms have included, but are not limited to, diarrhea, dizziness, rhinorrhea, anosmia, dysgeusia, sore throat, abdominal pain, anorexia, and vomiting. The abnormalities seen in chest X-rays of patients with COVID-19 vary, but bilateral multifocal opacities are the most common. The abnormalities seen in computed tomography of the chest also Downloaded from https://www.covid19treatmentguidelines.nih.gov/ on 7/6/2022 COVID-19 Treatment Guidelines 13 vary, but the most common are bilateral peripheral ground-glass opacities, with areas of consolidation developing later in the clinical course of COVID-19.31 Imaging may be normal early in infection and can be abnormal in the absence of symptoms. Common laboratory findings in patients with COVID-19 include leukopenia and lymphopenia. Other laboratory abnormalities have included elevated levels of aminotransferase, C-reactive protein, D-dimer, ferritin, and lactate dehydrogenase. Although COVID-19 is primarily a pulmonary disease, emerging data suggest that it also leads to cardiac,32,33 dermatologic,34 hematologic,35 hepatic,36 neurologic,37,38 renal,39,40 and other complications. Thromboembolic events also occur in patients with COVID-19, with the highest risk occurring in critically ill patients.41 The long-term sequelae of COVID-19 survivors are currently unknown. Persistent symptoms after recovery from acute COVID-19 have been described (see Clinical Spectrum of SARS-CoV-2 Infection). Lastly, SARS-CoV-2 infection has been associated with a potentially severe inflammatory syndrome in children