Los Angeles County health officials on Monday said they are recommending everyone wear a mask in indoor public places – regardless of whether they’ve been vaccinated for COVID-19 -- due to the rapid spread of the highly contagious Delta variant.
The recommendation, which officials described as a precautionary measure, comes after the Delta variant comprised "nearly half of all variants" sequenced in the county during the week ending June 12, according to a release by the Los Angeles County Department of Public Health.
"Until we better understand how and to who the Delta variant is spreading, everyone should focus on maximum protection with minimum interruption to routine as all businesses operate without other restrictions, like physical distancing and capacity limits," the statement read.
The Centers for Disease Control and Prevention (CDC) noted the Delta variant is now responsible for roughly one in every five new COVID-19 cases across the U.S.– a jump from one in every 10 a week ago.
The recommendation comes weeks after the CDC said vaccinated people can go most places without masks. Fully vaccinated individuals were still advised to wear masks while in crowded indoor settings such as while on public transportation and in hospitals, prisons, and homeless shelters.
"While COVID-19 vaccine provides very effective protection preventing hospitalizations and deaths against the Delta variant, the strain is proving to be more transmissible and is expected to become more prevalent," county Public Health Director Barbara Ferrer said in a statement. "Mask wearing remains an effective tool for reducing transmission, especially indoors where the virus may be easily spread through inhalation of aerosols emitted by an infected person."
Health officials noted that fully vaccinated people appear to be well protected from the Delta variant. People who received one vaccine dose of either Pfizer or Moderna are not as well-protected, they added.
The U.S. has a higher vaccination rate than many countries struggling with the variant, and daily infection rates have fallen sharply in the U.S. in the last few months as more Americans have gotten the vaccine.
Last week, about 60.5% of Californians have now received at least one dose of the COVID-19 vaccine, reports said. As of Monday, more than 153 million people are currently fully vaccinated in the U.S," according to the CDC.
There is no "widespread scientific consensus" as to whether the highly contagious Delta variant causes more serious illness than other strains," according to the Los Angeles Times.
Fox News' Brie Stimson contributed to this report