Herd Immunity: What Happened In California?
California is currently thouight to be the most-improved US state for COVID, having reversed the late 2020 surge soon after the new year, with no new third surge as happened in the US northeast and Canada. But since Los Angeles County accounts for a quarter of the state's population, much of this success is attributable to LA County's performance. Although Los Angeles and San Francisco Counties are both in the least restrictive "yellow" tier, San Francisco's population is less than a million, while LA County's is over ten million. The chart above shows cumulative totals for LA County cases and deaths, as well as case mortality rate, since the start of the pandemic. While the numbers, being cumulative, don't go down, they do show how the spread of the disease has been mitigated. More important, the dark curve at the bottom of the graph, reflecting cumulative deaths, shows a much more gradual curve than the light pattern at the top, which is cases. The ov...