COVID is surging again in California. How CDC’s indoor mask guidance will affect the state

The U.S. Centers for Disease Control and Prevention on Tuesday issued new guidance saying people should once again wear masks in indoor public settings, regardless of vaccination status, in areas with elevated levels of COVID-19 spread — a classification applying to a vast majority of California by population, including the entire Sacramento region.

Dr. Rochelle Walensky, director of the CDC, announced the new guidelines in a media briefing Tuesday. Walensky said that due to the risk posed by the Delta variant, masks are recommended in areas with transmission rates classified as “high or substantial.”

The CDC defines “high” transmission as more than 100 cases per 100,000 residents over the past seven days, and “substantial” as between 50 and 100 per 100,000.

The two categories cover nearly two-thirds of all counties nationwide, according to a CDC map updated Monday.

The list includes 45 of California’s 58 counties combining for roughly 96% of the state’s 39.5 million residents. The most populous counties not currently considered to have high or substantial transmission rates are Tulare, Monterey, San Luis Obispo and Santa Cruz.

The new guidelines mark a reversal from the CDC’s position in May, when federal health officials had said it was safe for the fully vaccinated to forgo masks in many indoor settings. Many states that had mask requirements either lifted or loosened them soon after, including California, which waited a few weeks but ended its mask mandate for fully vaccinated residents on June 15.

Walensky said the reversal was due to new evidence suggesting vaccinated people infected with the Delta variant “may be contagious and spread the virus to others.”

“This new science is worrisome, and unfortunately warrants an update to our recommendations,” Walensky said.

Asked during a news conference in Fresno shortly before the CDC’s updated guidance was officially released, California Gov. Gavin Newsom said the state would be able to provide more information on its own mask policy soon.

“As soon as we avail ourselves to the details, some of the tiering strategies which we’ve been in dialogue with the CDC on, we’ll make some comments in very short order,” Newsom said.

The California Department of Public Health in an emailed statement to The Sacramento Bee wrote: “We are doing a full review of the updated recommendations released by the CDC today and will evaluate existing guidance to determine the best path forward to protect Californians from the spread of COVID-19 and the highly contagious Delta variant.”

Cases are now soaring in many parts of the country, especially in states and regions with low vaccination rates, as the highly infectious Delta variant spreads.

Masks in the Sacramento region?

All six counties in the capital region — Sacramento, El Dorado, Placer, Sutter, Yolo and Yuba — meet the criteria for the new CDC mask recommendation. Case rates over the past week range from around 70 per 100,000 in El Dorado, Placer and Yolo to about 120 in Sacramento and 150 in Yuba, according to California Department of Public Health data updated Tuesday.

Some local health offices report higher rates than the CDPH figures; Sacramento County on its own data dashboard Monday recorded its daily case rate at 19.9, or about 140 per 100,000 over the past week, almost triple the masking threshold under the new federal guidelines.

The state retired its reopening “Blueprint” framework and dropped most COVID-19 restrictions in mid-June, putting most of the onus on individual counties.

Los Angeles, the nation’s most populous county at 10 million residents, on July 17 returned to a mask mandate, citing explosive spread of the Delta variant. Sacramento, Yolo, Fresno and most Bay Area counties that same week issued similar advisories, but as strong recommendations rather than mandates.

On Tuesday, Yolo County announced it will return to an indoor mask mandate that begins this Friday. The mandate will apply to indoor public spaces, such as grocery stores, and will remain until the case rate falls below two per 100,000 for seven consecutive days.

In a news release, the county said that the daily case rate has risen from “1.2 to 10.0 per 100,000 residents” since the state dropped a majority of its pandemic restrictions. Officials attribute the growth of rising cases, positivity rates and hospitalizations to the Delta variant.

Officials in Sacramento, El Dorado and Placer counties told The Sacramento Bee in emailed responses Tuesday afternoon that they were awaiting updated guidance from the state before implementing any changes to local policies.

Placer County health director Dr. Robert Oldham in an emailed statement said the county is “evaluating the CDC’s changes announced today, along with (Placer’s) local data.”

Oldham called it “reasonable for vaccinated people, especially those who may be around the immunocompromised or immunocompromised themselves, to take added precautions given the increasing rates of transmission.”

Officials from Sutter and Yuba counties did not immediately respond to The Bee’s requests for comment.

COVID-19 activity is rising steeply in California, as it is across most of the U.S., due to the Delta variant. The Golden State’s test positivity rate since July 1 has spiked from 1.6% to 5.4%, CDPH reported Tuesday. Hospitalizations with COVID-19 have surged from under 1,100 to 3,200 since the start of the month.

Both CDPH and the CDC have said Delta recently made up about 83% of sample cases tested for variants.

The Bee’s Zaeem Shaikh contributed to this story.