Two days after the Los Angeles Public Health Department announced that the much-talked-about UK variant of Covid-19, known as B.1.1.7, had been identified in the region, the California Department of Public Health revealed that another lesser-known strain had been circulating in the county as well.

Known as L452R, the newly announced arrival was first identified in Denmark in March. It showed up in California as early as May.

Dr. Charles Chiu, a virologist and professor of laboratory medicine at UCSF who, in concert with state authorities, has been genetically sequencing test samples to identify new variants said early indications are the L452R might be less susceptible to the currently approved vaccines, but more investigation is needed.