On December 1, the Centers for Disease Control and Prevention (CDC) issued a health advisory on the Omicron variant. Omicron, a new SARS-CoV-2 variant, has been identified in many countries, including the United States, and is categorized as a Variant of Concern by the U.S. government and the World Health Organization (WHO). Because little is known about Omicron currently, it is important for the public health and medical communities as well as the general public to remain vigilant to reduce potential exposure. This Health Alert Network (HAN) Health Advisory summarizes current knowledge about Omicron and provides recommendations on how to detect the Omicron variant within the United States as soon as possible to mitigate its spread.
Early reports are that the clinical signs and symptoms of COVID-19 from infection with the Omicron variant are similar to those of other variants and may also be absent (asymptomatic). As CDC and public health officials work to identify cases of COVID-19 with the Omicron variant, it is important to take a travel history for all suspected or confirmed COVID-19 cases. If the case is confirmed and there is a history of international travel within 14 days before symptom onset or positive test (if asymptomatic), the local health department should be notified about the travel history. Health departments should also be notified about household contacts or close contacts of individuals who are confirmed to have the Omicron variant.
The utility of travel history to identify Omicron cases will likely decline as domestic community transmission becomes more prevalent. With low levels of domestic community transmission, travel history may be a good screening tool to identify cases of possible Omicron.
There are no data yet available about the effectiveness of monoclonal antibodies and antiviral therapies (e.g., molnupiravir) against the Omicron variant. Whether severity of disease due to Omicron will differ from that of disease caused by other variants is currently unknown. At this time, the CDC recommends professionals continue to closely follow National Institutes of Health treatment guidelines for COVID-19.