This variant had been found in at least 48 U.S. states as of Sunday, since the first case in the country was detected in California on Dec. 1.
On Monday, U.S. biotechnology company Moderna announced that preliminary data suggests its COVID-19 booster shot appears to increase antibody levels against the Omicron variant
The currently authorized 50-microgram booster of Moderna's COVID-19 vaccine mRNA-1273 increased neutralizing antibody levels against Omicron about 37-fold compared to pre-boost levels, and a 100-microgram booster dose increased neutralizing antibody levels about 83-fold.
A 100-microgram booster dose was "generally safe and well tolerated," according to the company. But there was a trend toward slightly more frequent adverse reactions following the 100-microgram booster dose relative to the authorized 50-microgram booster dose.
To respond to the highly transmissible Omicron variant, Moderna will continue to rapidly advance an Omicron-specific booster candidate into clinical testing in case it becomes necessary in the future, said Stephane Bancel, CEO of Moderna.
The Omicron variant had been found in at least 48 U.S. states as of Sunday, since the first case in the country was detected in California on Dec. 1. It has taken the hold to become the dominant COVID-19 variant in the U.S. as more people are traveling and gathering for holidays.
The infection cases caused by Omicron amounted to 73.2 percent of all infection cases in the week ending Dec. 18, from 12.6 percent of all infection cases in the week ending Dec. 11, according to the U.S. Centers for Disease Control and Prevention (CDC).
The unprecedented infectiousness of the Omicron variant and its possible ability to evade the immune system have stoked concerns across the nation. However, experts said preliminary data suggest the new variant appear to cause less severe symptoms and hospitalizations.