In the United States, immigration status has long created hierarchies within our society, where some can participate fully in public life, while others are excluded. These divisions have serious consequences for our communities, including when it comes to public health. A research project led by the University of California, Santa Cruz recently uncovered a particularly alarming example of this effect by looking back on excess deaths in California throughout the course of the COVID-19 pandemic.
Alicia Riley , an associate professor of sociology at UC Santa Cruz and core faculty member in the campus’s Global and Community Health Program, led a team of researchers from UCSF Stanford, MIT, and Boston University in modeling pandemic-related excess mortality in California adults across immigration statuses and a wide range of other socioeconomic factors. The study found that pandemic-period relative excess mortality was twice as high among potentially undocumented immigrants as among those who appeared to be documented immigrants.
Between March 2020 and May 2023, there was an estimated 55% increase in the death rate above pre-pandemic levels among potentially undocumented immigrants, who were born outside the U.S. and lacked a valid social security number, compared to a 22% increase among immigrants who appeared to be documented, who were foreign-born with a reported valid social security number, and a 12% increase in mortality among U.S.-born citizens.
“My main takeaway from this study was just how high excess mortality was when we looked specifically at people who were potentially undocumented immigrants, regardless of race or ethnicity,” Riley said. “A 55% increase in deaths above what was normal prior is really shocking, on a community level. Families are still living with the consequences of those deaths today.”
Uncovering an overlooked variable behind pandemic inequities
While racial and ethnic inequalities in COVID-19 deaths have previously been well studied, Riley’s new paper is the first to examine the interplay of immigration status with other sociodemographic factors. In California, people born in Latin America make up the largest share of the immigrant population, yet there had been no prior data indicating how specific immigration statuses might play into the higher rate of COVID-19 deaths among the state’s Latino population.
“In the absence of data and the rush to explain things, I saw some really terrible examples of stereotyping early in the pandemic,” Riley said. “Even some county public health departments were trying to use cultural stereotypes to explain the high death rates among Latinos or pointing to comorbidities. But there was no scientific evidence that these things were driving the trends.”
Riley and her team set out to counteract harmful narratives by examining societal factors that might be behind the disparities, particularly immigration status. Researchers analyzed death certificates of all California residents aged 25 and older who died of natural causes between 2016 and 2023 in California. Death certificates indicate a person’s country of birth and whether they have a valid social security number, so by combining these two factors, the team classified individuals as either U.S.-born, those who appeared to be documented immigrants, or immigrants who may have been undocumented.
Across these immigration statuses and a range of other factors—like sex, age, race/ethnicity, educational attainment level, and occupation type—the team then looked for differences in pandemic-era survival outcomes. They modeled absolute and relative excess mortality from March 2020 through May 2023, based on baseline mortality from the pre-pandemic period and incorporation of seasonal variables.
The findings showed a very clear gradient in pandemic survival outcomes within most of the sociodemographic subgroups examined. Immigrants who were potentially undocumented generally had the worst outcomes, while immigrants who appeared to be documented survived at markedly higher rates, and U.S.-born people had the best outcomes. Of all subgroups, the hardest hit by excess pandemic deaths were Latino essential workers who were potentially undocumented. They experienced a staggering 91% increase in deaths over pre-pandemic levels. In contrast, the white U.S.-born subgroup experienced only an 8% increase in death.
“It’s clear from these findings that some subgroups had a very different experience in the pandemic than others, and that’s especially surprising since there were many pandemic-era policies in California that were intended to provide universal protection, like lockdowns and free testing,” Riley said. “Even in the face of those protections, risk was not experienced equally. Mortality was clearly stratified by immigration status, and that should raise alarms.”
Understanding the unique public health risks immigrants face
The new paper discusses possible explanations for the inequities that researchers found. Undocumented immigrants were more likely to work in jobs where they faced heightened risk of workplace exposure to COVID-19, and they also lacked access to benefits like paid sick leave, public medical insurance, and unemployment insurance, which were all critical determinants of health during the pandemic.
Additionally, the stress undocumented immigrants experience from the threat of arrest, detention, and deportation affects their immune systems in ways that may put them at greater risk of severe disease from infections like COVID-19. Fear of potentially revealing one’s immigration status can also dissuade people from seeking emergency medical care or reporting health related safety violations in the workplace.
In the aftermath of the pandemic, California and other states expanded Medicaid access to undocumented immigrants, which Riley’s findings suggest could potentially help reduce the death toll of a similar future pandemic. But these policies are now being rolled back amid budget woes and shifting federal policy. And new Trump Administration policies, like increasingly aggressive immigration enforcement tactics and the removal of prohibitions against immigration enforcement in health care settings, could actually worsen the next public health crisis.
To better protect the health of our communities, Riley recommends that undocumented immigrants be more fully included in public safety net and disaster response programs.
“Overall, these findings really make me think about the role that immigrant exclusion in our society plays in exposure risk for infectious diseases and delays in receiving health care that can make the difference between death and survival,” she said. “There are very close connections between how we enforce immigration policy and the health of families across our communities. We really need to be thinking about how we can expand access to things like worker protections, health insurance, and paid leave, so that everyone is truly protected.”