The official said that while the Centers for Disease Control and Prevention are reporting an increase in infections and hospital admissions from the virus, overall levels remain low.
On Thursday, Moderna said initial data showed its updated COVID-19 vaccine is effective against the "Eris" and "Fornax" subvariants in humans.
Moderna and other COVID-19 vaccine makers Novavax,Pfizer and German partner BioNTech have created versions of their shots aimed at the XBB.1.5 subvariant.
Pending approval from health regulators in the United States and Europe, the companies expect the updated shots to be available in the coming weeks for the autumn vaccination season.