They're already there. The opportunity just needs to appear.
Across eight American cities, researchers have uncovered a quiet paradox at the heart of public health: nearly everyone who walks into an emergency department knows the flu vaccine exists, yet more than half haven't received one. A UC Riverside study of over three thousand ED patients suggests that the very places people turn to in crisis may also be the places best positioned to prevent the next one — particularly for those who have no other door into the healthcare system.
- Flu kills 650,000 people globally each year, yet fewer than half of American adults got vaccinated last season — a stubborn gap that existing healthcare channels have failed to close.
- The burden falls hardest on those without primary care providers, who are more than twice as likely to be unvaccinated, along with uninsured patients and African American communities already navigating systemic barriers.
- Emergency departments, long seen as reactive spaces, are quietly becoming the only healthcare touchpoint for millions of medically underserved people — making them an untapped venue for prevention.
- When unvaccinated ED patients were asked directly, more than one in three said they would accept a flu shot on the spot, suggesting the gap is less about resistance than about absent opportunity.
- Researchers argue that targeted educational messaging and on-site vaccination programs could transform EDs into a public health safety net — but only if hospitals choose to embrace that expanded role.
Nearly everyone knows the flu vaccine exists. But knowing and getting vaccinated are two very different things — especially if you don't have a doctor's office to call your own.
Researchers at UC Riverside surveyed 3,285 adults passing through emergency departments in eight American cities between April and December 2024. The findings revealed a stark disconnect: 96% of patients had heard of the influenza vaccine, yet 58% hadn't received one in the past year. The study, published in the Journal of Emergency Medicine and led by Dr. Robert Rodriguez, points to emergency departments as an underutilized opportunity to close this gap.
The disparities were sharp. Patients without a primary care provider were more than twice as likely to be unvaccinated. Uninsured patients and African American patients also showed lower vaccination rates. More than one in five participants had no regular doctor at all — meaning the ED was, for them, the healthcare system.
When asked whether they'd accept a flu shot if offered during their visit, 37% of unvaccinated patients said yes. Those who declined cited concerns about side effects, a desire for more information, or feeling too ill in that moment. The barriers, researchers noted, are mostly about information and opportunity — not deep resistance.
Influenza kills an estimated 650,000 people worldwide each year. Dr. Rajesh Gulati, a coauthor on the study, framed the stakes plainly: EDs are often the only healthcare touchpoint for medically underserved populations, and there is real potential to reach people who may never set foot in a primary care clinic. First author Sanya Dhama argued that emergency departments could function as a public health safety net for prevention, not just acute care — a role they are currently underutilizing.
The people who need vaccination most are often the least likely to receive it through traditional channels. But they are already showing up at emergency departments. The question is whether hospitals will recognize the moment and act on it.
Nearly everyone knows the flu vaccine exists. But knowing and getting vaccinated are two different things, especially if you don't have a doctor's office to call your own.
Researchers at UC Riverside surveyed 3,285 adults walking through emergency departments in eight American cities—Chicago, Detroit, Durham, Philadelphia, Fresno, Los Angeles, San Francisco, and Sylmar—between April and December 2024. What they found was a stark disconnect between awareness and action. Ninety-six percent of patients had heard of the influenza vaccine. Three-quarters said they'd received one at some point in their lives. Yet 58.4% hadn't gotten a flu shot in the past year, meaning they were behind on current recommendations. The study, published in the Journal of Emergency Medicine and led by Dr. Robert Rodriguez, a professor of medicine at UCR's School of Medicine, suggests that emergency departments might be the place to close this gap.
The disparities were unmistakable. Patients without a primary care provider were more than twice as likely to be unvaccinated. Those without insurance and African American patients also showed lower vaccination rates. More than one in five study participants reported having no regular doctor at all. For these people, the emergency department often represents their only real contact with the healthcare system—a moment when they're already in the building, already talking to medical staff, already present.
When researchers asked unvaccinated patients whether they'd accept a flu shot if offered right there in the ED, 37% said yes. That's a substantial number of people willing to be protected if the opportunity simply appeared in front of them. Among those who declined, the reasons were predictable: worry about side effects, desire for more information about vaccines and the disease itself, or feeling too sick at that particular moment to add another medical procedure to the visit.
Influenza kills an estimated 650,000 people worldwide each year. In the United States, fewer than half of adults received a flu vaccine during the 2023–2024 season, despite decades of public health recommendations. The virus remains a major threat, yet vaccination coverage remains stubbornly low, particularly among populations already struggling with healthcare access.
Dr. Rajesh Gulati, a coauthor and professor of medicine at UCR, framed the opportunity plainly: emergency departments are often the only healthcare touchpoint for medically underserved people. The study showed there's real potential to reach people who might never walk into a primary care clinic and help them get protected. Sanya Dhama, the paper's first author and a medical student at UCR, emphasized that EDs could function as a public health safety net not just for emergencies but for prevention—a role they're currently underutilizing.
Dr. Rodriguez suggested that educational messaging and targeted outreach could push acceptance even higher. The barriers aren't insurmountable; they're mostly about information and opportunity. If emergency departments expanded vaccination programs, offering flu shots alongside acute care, the potential impact could be significant: fewer cases of influenza, fewer hospitalizations, fewer deaths—particularly among the populations most vulnerable to severe illness and least likely to have access to routine preventive care elsewhere.
The study was supported in part by the National Institute of Allergy and Infectious Diseases. The research team included collaborators from UCLA, UCSF, Rush University Medical Center, Wayne State University, Thomas Jefferson University Hospital, and Duke University School of Medicine. What emerges from their work is a simple but powerful insight: the people who need vaccination most are often the ones least likely to get it through traditional channels. But they're already showing up at emergency departments. The question now is whether hospitals will recognize this moment and act on it.
Notable Quotes
Emergency departments are often the only point of contact with the health care system for many patients. There is a substantial opportunity to reach people who may not have access to primary care and help close important gaps in influenza vaccination coverage.— Dr. Rajesh Gulati, coauthor, UCR School of Medicine
Emergency departments can serve as a critical public health safety net—not only for acute care, but also for preventive services such as influenza vaccination.— Sanya Dhama, first author and medical student at UCR
The Hearth Conversation Another angle on the story
So the study found that most ED patients haven't had a flu shot this year, even though they know the vaccine exists. Why does that gap matter so much?
Because knowledge alone doesn't protect you. You can be aware that something exists and still never access it. For people without a regular doctor, there's no standing appointment, no reminder call, no routine visit where vaccination happens automatically. The ED becomes their only real contact with healthcare.
And the study found that 37% of unvaccinated patients would accept a shot if offered during their ED visit. That seems like a significant number.
It is. It's not that people are refusing vaccines outright. It's that the opportunity never presents itself. They're already there, already talking to medical staff. If someone offered it in that moment, more than a third would say yes. That's a massive untapped resource.
What about the people who said no? What were their concerns?
Mostly practical things—fear of side effects, wanting more information about how the vaccine works or what flu actually does to you, or just feeling too unwell at that particular moment to add another procedure. These aren't ideological objections. They're answerable with education and timing.
The study highlighted disparities—uninsured patients, African American patients, people without primary care. Why do those specific groups show up in the data?
Because they're the ones most likely to lack routine healthcare access. If you don't have insurance or a doctor, you're not getting preventive care anywhere else. The ED becomes your only option. And that's exactly where the study says we should be intervening.
So the argument is that EDs should become vaccination sites, not just emergency care centers?
Not instead of emergency care—alongside it. EDs already see the people who need protection most and have the least access to it elsewhere. It's not about changing their core mission. It's about recognizing that prevention and acute care aren't separate. They happen in the same moment, in the same place, with the same patient.