Current COVID case data would put Alameda County in purple tier of old reopening plan By Eli Walsh article OAKLAND, Calif. - Alameda County would be in the most restrictive tier of the state's former pandemic reopening plan based on the county's current COVID-19 case data, the top county health official said Tuesday. In a briefing to the Alameda County Board of Supervisors, county Health Officer Dr. Nicholas Moss said the county's seven-day average number of new cases per day per 100,000 residents is up to 17 and likely to increase even further. The case numbers mean Alameda County would be firmly within the most restrictive purple tier of the old four-tiered reopening system, which included counties with case rates of seven or more per 100,000 residents.