H5N1: Have We Forgotten About Avian Influenza?

Growing geopolitical tensions, war, social unrest, a partial government shutdown, and an imminent loss of measles elimination status are just a handful of the issues we’re facing in the United States. In many ways, it’s not surprising that some issues would get put on the back burner, and that’s often the case for outbreaks of infectious disease. While H5N1 is not a novel disease, it is a highly pathogenic avian influenza that requires continuous monitoring of commercial and backyard flocks, wild birds, livestock, and mammals, as it’s considered a major threat not only to the poultry industry but also to overall animal health and the economy.¹

The potential for spillover to other animals and humans is one that particularly worries us. While H5N1 does not efficiently spread between humans, the potential for mutations that could increase transmissibility and disease severity increases with each new case. “It’s rampant in wild and domestic birds and cattle. These animals serve as perfect mixing vessels to generate a flu virus that might jump to humans,” Nancy Connell, PhD, professor and director for research, Division of Infectious Disease, Department of Medicine, Rutgers New Jersey Medical School, noted regarding H5N1. “The [US Department of Agriculture] plans to maintain a robust surveillance system to keep track of how this virus is moving through these animal populations, so we’ll be ready if and when it makes the jump into the human population.”

The US has been struggling to respond to an unprecedented outbreak since 2024, during which not only birds were impacted, but also dairy farm animals and humans. According to the Centers for Disease Control and Prevention, since 2024, in humans, there have been 71 cases and 2 deaths. Of these 71 human cases, 41 were related to exposure from dairy herds (cattle), 24 from poultry farms and culling operations, 3 via other animal exposure (backyard flocks, wild birds, etc), and 3 were from an unknown origin.² Cattle herds were impacted across 19 states, with 1088 confirmed cases.³ Early efforts to expand testing, such as the monitoring of retail milk, helped improve surveillance for the virus, but there has been growing concern that the significant cuts to federal health agencies are translating to larger gaps in not only disease detection, but also response.⁴

The reality is that this outbreak presents unique challenges for sustaining support for response efforts; it is not confined to a single species and has caused mostly mild illness in both humans and dairy cattle. For some, the fears around H5N1 were not necessarily about human cases, given that they presented with mild symptoms, but about larger economic stability and the disruption to the US and global food systems.⁵ For public and animal health practitioners, though, the outbreak highlighted the neglected facets of One Health and that responding to such outbreaks requires multisectoral collaboration and coordination, as well as ongoing federal support.

A Meeting of Minds and a Path Forward

In early March, the Johns Hopkins Bloomberg School of Public Health hosted the H5N1 Influenza Preparedness and Response Forum, which brought together experts in animal health, virology, public health and health care response, medical countermeasure development, and health security to discuss where we’re at and where we need to be. I was fortunate to attend and speak on health care response, and a consistent theme throughout the discussions was the converging risks posed by this increasingly neglected outbreak, alongside the remarkable dedication of those working in response. Experts spoke to viral evolution and host response, surveillance and monitoring across species, and what is necessary to contain not only this outbreak, but also future ones. “No one wants to imagine another pandemic. But ignoring the fact that H5N1 is now in birds everywhere and could jump to humans is not a good strategy. In the last 5 years, we have had to cull 200 million birds because of H5N1. We need to think anew about how we can reduce the threat to agriculture and to human health,” stated Gigi Gronvall, PhD, professor, Johns Hopkins Bloomberg School of Public Health.

Across the workshop, several key themes emerged, with many speakers noting that the response to the H5N1 outbreak reflected broader systemic issues in the post COVID-19 pandemic US. Discussion focused on several areas of vulnerability that the outbreak has highlighted: personal protective equipment and physical protection for workers, biosecurity practices on farms, compensation and financial support structures to support farmers and encourage reporting, data collection and transparency, community engagement and culturally competent communication, health system preparedness, and coordination across agencies.

“With the US federal government completely abandoning pandemic preparedness and reducing response capability to drinking whole milk and going for a walk, we face grave preventable security threats as well as preventable diseases. If the government will not take action against the threat posed by H5N1, I am honored to be part of the scientific, public health, and policy-making community rising to the challenge,” said Angela Rasmussen, PhD, virologist at the Vaccine and Infectious Disease Organization at the University of Saskatchewan. A key point of discussion within this meeting—and across the response community—has been biosurveillance, not just in animals, but also in people. As human cases have mostly involved mild illness, it can be difficult to encourage people to get tested or even test across farms to identify undetected cases. One consistent theme in the discussions was the vulnerability of those most at risk, particularly farm workers, many of whom are migrants and may fear immigration enforcement, especially amid increased activity by US Immigration and Customs Enforcement.

The intersection of aggressive deportation policies and the H5N1 outbreak is one we cannot ignore, as it ultimately undermines public health surveillance and response. “Dairy and poultry workers have accounted for most cases of the bird flu in the US, and preventing and detecting cases among them is key to averting a pandemic. But public health specialists say they’re struggling to reach farmworkers because many are terrified to talk with strangers or to leave home,” journalist and evolutionary biologist Amy Maxmen, PhD, said.⁶ It’s not just the case detection, contact tracing, and outbreak mitigation that are at risk, though. Cuts to federal response agencies, growing hesitation around vaccines, and varying trust in health leadership could make a response with medical countermeasures challenging.

Outside of another public health emergency of international concern, would the American public support a widespread vaccination effort? A human vaccine for H5N1 is in clinical trials, but vaccination in poultry presents other issues, as some countries ban meat imported from vaccinated animals.⁷ Will economic incentives override public health concerns? While medical countermeasures are essential to response, they must be paired with strong surveillance, outbreak mitigation, and improved access to care for both human and animal populations. However, as attention shifts, there is a growing concern that H5N1 is being treated as yesterday’s problem, potentially undermining the engagement and support needed to confront this persistent threat.

The H5N1 outbreak has tested US preparedness in many ways, highlighting critical areas that must be strengthened to sustain health security: stable funding for One Health and pandemic preparedness; stronger coordination across federal, state, and local agencies and between public health, agriculture, and wildlife sectors; more integrated surveillance and data sharing across human and animal health systems; improved protections for agricultural and other frontline workers; meaningful efforts to address social inequities and support vulnerable populations; rebuilding public trust in science and the federal response; clear and consistent risk communication; and sustained investment in research and workforce capacity.

References

1. Avian influenza. USDA. Updated March 3, 2026. Accessed March 13, 2026. https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza

2. A(H5) bird flu: current situation. CDC. March 6, 2026. Accessed March 13, 2026. https://www.cdc.gov/bird-flu/situation-summary/index.html

3. Situational update: March 13, 2026. USDA APHIS. Accessed March 13, 2026.https://www.aphis.usda.gov/h5n1-hpai

4. Tarbuck NN, Franks J, Jones JC, et al. Retail milk monitoring of influenza a (H5N1) in dairy cattle, United States, 2024-2025. Emerg Infect Dis. 2026;32(2):238-241. doi:10.3201/eid3202.251332

5. Morel G, Pham A, Morgenstern C, et al. An outbreak of highly pathogenic avian influenza H5N1 could impact the dairy cattle sector and the broader economy in the United States. Commun Earth Environ. 2026;7(1):135. doi:10.1038/s43247-025-03153-9

6. Maxmen A. Trump’s immigration tactics obstruct efforts to avert bird flu pandemic, researchers say. KFF Health News. April 10, 2025. Accessed March 13, 2026.
https://kffhealthnews.org/news/article/bird-flu-trump-immigration-raids-farmworkers-threats-california-michigan/

7. US and Canada ease ban on French poultry imposed after bird flu vaccination. Reuters. January 20, 2025. Accessed March 13, 2026. https://www.reuters.com/business/healthcare-pharmaceuticals/us-canada-ease-ban-french-poultry-imposed-after-bird-flu-vaccination-2025-01-20/