It’s quartile 4, the highest risk. Quartile 1 is the lowest risk, or healthiest, areas. They were at 1.6M already when this initiative was announced.
Edit - I think the arrow least-to-most in your graphic might be backwards, but I’m tired and maybe not thinning correctly. It’s 4th quartile that’s lowest health though, because they used the same quartile to prioritize teacher vaccinations in SD last week.
You have it backwards. Quartile 1 is the lowest income/worst outcomes and quartile 4 is higher income/better outcomes.
From ca.gov
The state is using the Healthy Places Index (HPI), which reflects 25 community characteristics
using data related to the economy, education, healthcare access, housing, neighborhoods, clean
environment, transportation, and social environment. California’s 1650+ ZIP codes have been
divided into four quarters based on the HPI Index. Those with the highest HPI scores correlate to
better health outcomes, while those with lower scores (first quartile) reflect worse health
outcomes. In general, higher HPI scores also correlate with higher household incomes, and lower
HPI scores correlate with lower incomes.
Allocation Formula: Starting with the March 2nd dose allocations delivered the week of
March 8, first doses will be allocated based on two steps:
1. Eligible Population: 70:30 based on the geographic distribution of the
population eligible for the vaccine, with 70 percent based on age eligibility and 30
percent based on sector eligibility.
2. Double Allotment for Lowest HPI Quartile: Next based on the 70:30
split, zip codes in the first HPI quartile (i.e., those with the lowest 25 percent HPI
scores) will be allocated 40 percent of the state’s available vaccine doses. Since
approximately 40 percent of COVID cases and deaths are in the first HPI quartile,a similar percentage of doses should be administered in these communities. Each
of the remaining quarters of the ZIP codes will be allocated 20 percent of doses
on hand. This results in twice as much vaccine being available in ZIP codes with
the worst COVID outcomes throughout the pandemic. In short, the state will
double the amount of vaccines allocated to the lowest 25% of zip codes when
compared to the rest of the state.
This allocation formula will be in effect for two weeks (the March 2 and March 8
allocations). The allocation formula will be adjusted after two weeks to account for the Janssen (Johnson and Johnson) vaccine, the new eligibility policy on March 15 (for persons with high-risk medical conditions and disabilities), and the Third-Party Administrator (TPA) onboarding waves.