San Mateo County is now reporting that nearly 95 percent of residents 16 and older have received at least one dose of the COVID-19 vaccine. The 12- to 15-year-old population isn’t far behind, with 81 percent vaccinated locally.
Pacifica is now reporting 87 percent of its residents vaccinated.
The impressive numbers come with caveats. The current population numbers that dictate the city-level estimates are based on 2019 U.S. Census Bureau data, which is now 2 years old. That’s because the Census Bureau won’t release 2020 data from its American Community Survey, the measure being used by the county to estimate population at the city and census tract levels, until December.
Even the county-level totals differ between sources by up to 10,000 residents. County Health Public Information Officer Preston Merchant wrote in an email to the Review that the Health Department is using Department of Finance data for overall county population, race and age statistics, because it is updated more frequently and is more precise than the federal resource. Because their sources differ, the county totals and city-level data can’t be combined.
That’s not the only asterisk that comes with the data. Population estimates for cities like Colma and Ladera, which are each reporting a 100 percent vaccination rate, come with the caveat that Census community survey underestimates of population may be skewing results. And Merchant wrote that the vaccination totals, which are sourced from the California Immunization Registry, or CAIR2, are constantly updated to fix inaccuracies in residency, race, age or other factors.
“There are always challenges with the data, which is sourced from dozens of providers, but there is work in all parts of the system to remove duplicates and reconcile,” Merchant wrote.
The county clarifies on its website that age, sex and race/ethnicity numbers come from Department of Finance projections and not the census. Reporting race and ethnicity data in particular, the statement reads, relies on self-attestation that may be missing, inaccurate or inconsistent.
Despite the imperfect and changing measures, county health officials wrote that providing any data, even with inaccuracies, is valuable.
“While the data may not be precisely accurate, they do suggest that racial and social inequities are still causing barriers to immunization, and this information guides further efforts in community engagement and outreach,” the website reads. “We are sharing this imperfect data publicly to maximize transparency and engage stakeholders in addressing the social and racial determinants of health.”
Residents who are now getting booster shots may also be slightly skewing the numbers. Merchant wrote that the county is not currently collecting data on third doses because there have been relatively few administered locally and because the county is focused on providing first and second doses. While local health care providers are administering third doses to immunocompromised residents, county health clinics are not. Merchant said he doesn’t expect the low number of boosters administered locally to have much effect on the totals.
That may change in the future, however, after the U.S. Centers for Disease Control and Prevention Director Rochelle Walensky recommended third doses for Pfizer recipients six months after vaccination for people 65 or older, long-term care residents and people working in high-risk environments like health care, teaching and first response. Boosters are also recommended for people ages 50 to 64 with underlying health conditions.
Her recommendation overrules the CDC’s Advisory Committee on Immunization Practices, which did not include high-risk workers for boosters, in favor of the Food and Drug Administration’s advice. No current recommendations or approvals for booster shots for the Moderna or Johnson & Johnson vaccine exist.
On Sunday at the Half Moon Bay vaccine clinic, Site Manager Tito Guerrero said he expects a slight uptick at the site following the news about booster recommendations. He’s been seeing anywhere from 15 to 40 patients per week at the Sunday site, which offers both the Pfizer and Johnson & Johnson vaccines.
“Once we heard about the variant, there was a small jump,” Guerrero said. “We expect it to pick up again for boosters.”