More parts of California will be allowed to further reopen their economies this week amid both growing optimism as the last coronavirus wave continues to recede and swirling concern that new variants of the virus threaten to imperil that progress.

According to the latest state data, seven counties will move from the purple tier — the strictest level in the state’s four-category reopening road map — into the more permissive red tier, effective Wednesday.

The advancement of Santa Clara, San Francisco, San Luis Obispo, El Dorado, Napa, Lassen and Modoc counties grows the number of counties that have progressed out of the purple tier to 18, and raises the number of Californians living outside the most restrictive category from about 1.6 million to 5 million, representing about 13% of the state’s population.

Counties are assigned to tiers based on three criteria: their average coronavirus case rates, which are adjusted based on the number of tests performed; testing positivity rate; and a health equity metric intended to ensure the positivity rate in poor communities of color does not significantly lag behind the overall county figure.

Read the full story at LATimes.com.