Masked California County’s Case Rates ‘Near-Identical’ to Nearby Maskless Counties, ‘Casting Doubt’ on Policy

Advocates for universal masking hit another snag after data showed that one California county, which recently lifted its mask mandate, experienced “near-identical” case rate curves as nearby counties, which did not have mask mandates in place.

Alameda County stood as the only county in the area that reimposed a mask mandate for the bulk of June. The rule went back into effect June 3, requiring individuals to wear a mask in “most indoor public settings.”

“We cannot ignore the data, and we can’t predict when this wave may end. Putting our masks back on gives us the best opportunity to limit the impact of a prolonged wave on our communities,” Alameda County Health Officer Dr. Nicholas Moss said at the time.

The county lifted the mandate three weeks later, on June 25. This was the only Bay Area county to have a mask mandate in place during that time period, setting up an interesting case study. And as it turns out, Moss’s statement did not come to fruition, as the mask mandate did not make a significant difference in the case rate, at least compared to nearby maskless counties.

SFGate cited data from the California Department of Public Health, showing the case rate for Alameda County — as well as Contra Costa, Santa Clara, and San Francisco — and found that the mask mandate made little to no difference:

The case rate curves for Alameda and Contra Costa counties are near-identical. Because the neighboring counties are similar in so many respects, if masking policy had an impact on pandemic outcomes, one would expect to see some sort of discrepancy in the graph.

While Santa Clara and San Francisco reported higher case rates and currently have a slightly higher 7-day case positivity rate, SFGate’s Eric Ting noted that these counties already “had higher case rates than Alameda County throughout the current surge, including pre-mask mandate.”

“Once the mandate was introduced, the three counties all followed the same trend line, casting doubt on whether the mask mandate did anything to curb transmission at the community level,” the report reads.

However, Moss refused to admit that the mask mandate was virtually useless.

“We believe the recent mask order contributed to the improvements we are now observing with COVID-19 in Alameda County,” he told the outlet, asserting that “conditions are more stable now than at the time the Order was put in place.”