‘Hot-Spot’ Strategy Gets More Californians Vaccinated

In addition to bringing isolation and illness to the world, the COVID-19 pandemic spotlighted the health disparities among Southern California communities.

By January 2021, when the first COVID-19 vaccines became available to the public, it was clear that some communities with fewer resources were seeing higher rates of illness and death due to COVID-19. Getting vaccines and making them widely available was a challenge in Southern California and across the nation.

At Kaiser Permanente, teams from the Southern California Permanente Medical Group and the Southern California Department of Research & Evaluation partnered to address the issue. A study outlining these efforts was published on March 13, 2023, in The Permanente Journal and is featured in the Department of Research & Evaluation’s 2022 Annual Report.

Limited socioeconomic opportunities, such as a good education and a stable job, as well as biased policies and attitudes disproportionately affect underrepresented populations and their health outcomes. These factors contributed significantly to the unequal access to vaccines that occurred throughout the United States in 2021, according to Reina Haque, PhD, an epidemiologist with the Department of Research & Evaluation, who was the senior author on the study.

‘Hot-spot’ strategy employed to address inequities

“To address the challenges of inequitable access to the COVID-19 vaccine in Southern California, Kaiser Permanente applied a community-oriented and geographic strategy aimed at reducing disparities in COVID-19 vaccination by ZIP codes,” said Haque.

This became known as the “hot-spot” strategy.

Researchers used analytical tools to assess the risk of COVID-19 in different communities within Kaiser Permanente’s 670 Southern California ZIP codes. This produced monthly lists of ZIP codes that required additional health care resources and vaccination strategies. Then the COVID-19 vaccination teams worked with Kaiser Permanente medical centers to get more people vaccinated in the identified ZIP codes.

They sent proactive texts, extended vaccination clinic hours, provided in-home vaccinations for home-bound patients, and had a mobile health vehicle with vaccines drive into neighborhoods. Health care providers at various pop-up clinics and in the mobile health vehicle vaccinated both Kaiser Permanente members and nonmembers.

“The strategy was effective in both creating awareness of inequities and guiding vaccination efforts toward the most vulnerable communities,” said Haque.

Strategy success leads to further efforts

By the end of 2021, this hot-spot strategy helped Kaiser Permanente achieve an overall vaccination rate of 81% among all Southern California members. Additionally, 2 out of 3 people who received a vaccination through the hot spot-guided mobile health vehicle were Hispanic or Black.

But the work didn’t stop there. This place-based approach to reducing vaccination disparities in underserved communities was quickly adapted to other health disparities.

In 2022, the strategy was used to address disparities in flu vaccination and diabetes control.

“After we had successfully employed this hot-spot vaccination strategy with COVID-19, we were able to refine how we analyzed the data and our approach to the social and economic factors impacting our members,” said Alexander Martos, DrPH, interim director for the Southern California Permanente Medical Group’s Equity, Inclusion, and Diversity department. “We are now in the process of operationalizing these hot spots with our vaccination and proactive care teams and look forward to exploring new health equity opportunities in the future.”

Read more inspiring stories that exemplify the spectrum of our research’s impact in the Southern California Department of Research & Evaluation 2022 Annual Report.