County public health officials say more than half of the available vaccines are now going to the hardest hit areas.
A change in the tier thresholds mean that could lead to a quicker move to a less-restrictive tier.
The county was initially anticipated to advance into the "red" tier later this month, with the rate of new daily COVID-19 infections expected to fall below the state-mandated threshold of 7 cases per 100,000 residents as early as Tuesday. If the county maintained that level for two weeks, it would move out of the "purple" tier and into the "red" tier.
The state, however, changed the thresholds for advancing through the four-tier Blueprint for a Safer Economy last week, taking into account the volume of vaccines being administered in hard-hit, lower-income communities across the state.
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The new thresholds could take effect as early as this week, when the state reaches the milestone of administering 2 million vaccine doses in those hard-hit neighborhoods.
When that happens, advancing to the "red" tier will require a county to have a new case rate of 10 per 100,000 residents -- a rate L.A. County will have already met for the required two weeks. Ferrer said that means the county will likely advance to "red" by the middle of next week.
"If this week's adjusted case rate remains below 10 new cases per 100,000 people, our understanding is that within 48 hours of the state announcing the vaccine trigger has been met, Los Angeles County, along with other counties with qualifying case rates, would move into the red tier," L.A. County Public Health said in a statement. "We will be working with the Board of Supervisors and our sector partners to prepare appropriate modifications to the Health Officer Order reflecting the County's move to the red tier."
Moving from the restrictive "purple" tier into the "red" tier will authorize the county to increase capacity limits at retail establishments and reopen indoor dining, fitness centers and movie theaters. However, the county is not bound by the state guidelines and could continue to impose stricter rules.
For instance, while the county currently allows outdoor dining in the "purple" tier, it still forbids restaurants from turning on television sets on their patios, as a way of preventing gatherings of sports fans. The state has no such restriction on restaurants.
Meanwhile, vaccination efforts in L.A. County continue to grow.
A mass vaccination site at the Antelope Valley Fairgrounds opened Monday. Officials say it can administer as many as 2,000 shots per day.
"This region has been very hard hit. It's geographically isolated, transportation is a problem," L.A. County Supervisor Kathryn Barger said.
"We are looking across the board throughout the entire region to get equity up in the Antelope Valley," she added.
As the number of vaccinated people continues to grow across the country, the Centers for Disease Control and Prevention eased some of its COVID-19 safety protocols.
Fully vaccinated Americans can gather with other vaccinated people indoors without wearing a mask or physical distancing, the CDC announced Monday.
The recommendations also say that vaccinated people can come together in the same way - in a single household - with people considered at low-risk for severe disease, such as in the case of vaccinated grandparents visiting healthy children and grandchildren.
City News Service and the Associated Press contributed to this report.