SACRAMENTO (CBS13) — Sacramento residents are once again being asked to mask up indoors as the county’s COVID-19 case rate increases and the Delta variant surges.

On Thursday, the Sacramento County Public Health Officer recommended that fully vaccinated people should once again start wearing a face mask indoors in settings where vaccination verification is not required.

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This means that masks are strongly recommended in such public settings as a grocery store or restaurant, but not in a workplace where employers ask for self-attestation of vaccination status.

County officials say the increase in daily COVID-19 cases appears to be due, in part, to the Delta variant.

“The drastic increase in cases is concerning – as is the number of people choosing not to get vaccinated,” said Sacramento County Public Health Officer Olivia Kasirye in a statement.

With Sacramento County leading the state in COVID infection rates, health leaders are urging people to get vaccinated. Only 47 percent of Sacramento County’s population has gotten the vaccine.

Sacramento County is the second area in the region to urge people to wear masks again. On Wednesday, Yolo County public health leaders also urged their residents to again start masking up.

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Data from Yolo County Public Health shows11 fully vaccinated people have become infected with the highly contagious Delta Variant all of which had viral loads consistent with being infectious.

“Based on the fact that about a quarter of the cases in Yolo County are among fully vaccinated people,” added Yolo County Public Health Officer Dr. Aimee Sisson.

Los Angeles, the most populous county in the nation with more than 10 million residents, also joined Sacramento on Thursday in urging everyone to wear masks indoors.

Dr. Jeffrey Klausner is a Professor of Population and Public Health Sciences at USC.

“If we want to get this epidemic under control it’s not about masking anymore that was very 2020, it’s actually about vaccinations,” he said.

He says vaccinations should remain a priority despite breakthrough cases and while Sacramento County is dealing with an increase in cases, he says every wave has a dropping point.

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“It’s not surprising to see ripples of infection you know like when you throw a stone in a pond that there be continued waves and overtime those waves will be less and less few and fewer,” he added.