What Public Health Won and Lost in 2025

It’s been a seismic year for public health—one that destabilized the foundations of institutions and processes that once felt solid.

The repercussions—seen in reductions to health care access, loss of federal public health jobs and programs, and diminishing public confidence in health agencies and science—have been experienced across the U.S.

But in many cases, these challenges have also created opportunities as the public health community worked to fill gaps left by funding cuts, firings at federal public health agencies, vaccine hesitancy, and a surge in vaccine-preventable diseases. 

There were also wins to celebrate and momentum on key issues going into 2026.

Setbacks, Challenges, and Causes for Concern

This year, the U.S. witnessed the upending of public health institutions and processes—and public health professionals got creative to fill the gaps.

Aid cuts disrupted global health.

The dismantling of USAID programs around the world caused confusion, chaos, and waste in global health. The consequences have been deeply felt in the global fights against malaria, HIV/AIDS, Africa’s historic cholera outbreak, and innumerable other health challenges.

A bright spot: Private funders have rallied to dedicate funds that could help offset some of the losses. 

Public health agencies were dismantled. 

Reductions in force and reduced funding at the FDA, CDC, and NIH challenged public health agencies and federal data collection and led some states to seek alternative data sources. Federal data collection systems were also dismantled, including key reports related to pregnancy, adolescent health, and hunger.

A bright spot: “While there is no full substitute for high quality federal data, this has led to new focus on innovations in how we collect and use data, with states and private groups stepping up. Over time hopefully this will mean that we will have a strong federal data environment, complemented by other sources, and with careful attention to what each can offer to provide data to inform public health decision-making,” says Elizabeth Stuart, PhD, AM, chair of Biostatistics. One example: Caitlin Rivers, PhD, MPH, a senior scholar at the Center for Health Security, has been covering seasonal illness data surveillance region by region in her Substack.

Vaccine hesitancy continued to spread—and vaccine-preventable diseases made a comeback.

Amid rising vaccine hesitancy driven by misinformation and disinformation, and declining childhood vaccination rates, the U.S. continues to see alarming resurgences of measles and whooping cough. And, setting the stage for broader reconsideration of childhood immunization policy, the Advisory Committee on Immunization Practices voted to withdraw a longstanding recommendation that newborns receive a hepatitis B vaccination at birth—without new evidence and against the strong consensus of medical groups that the change puts children at unnecessary risk.

A bright spot: “Medical societies, state departments of public health, and schools of public health are all stepping up to maintain vaccine recommendations that are based on evidence and have a history of working to reduce infectious disease burden,” says Andrew Pekosz, PhD, a professor in Molecular Microbiology and Immunology.

Breakthroughs

In a year dominated by public health challenges, there were important wins worth celebrating.

A global pandemic treaty was finally signed.

After three years of negotiations and rewrites, 194 countries—notably, not including the U.S.—“made history” by agreeing to a plan to improve how the world prevents, prepares for, and responds to future pandemics, including making vaccine access more equitable than it was during COVID-19.

A game-changing shot entered the fight against HIV.

Despite dramatic funding setbacks, this year the global HIV response gained a “transformative” tool: lenacapavir. The twice-yearly PrEP injectable is a highly effective, long-acting alternative to existing HIV prevention tools and a huge win for communities facing challenges with regular adherence and stigma in accessing health care.

Some countries exceeded expectations on HPV vaccination.

A major push by Gavi, the Vaccine Alliance and lower-income countries to extend access to the HPV vaccine beat its own deadline. The effort helped protect some 86 million girls in high-risk countries from cervical cancer, and prevented an estimated 1.4 million future deaths. And in Scotland, research showed that HPV vaccination efforts have all but erased cervical cancer in fully vaccinated women.

U.S. cities were less violent.

2025 has seen one of the most dramatic reductions in homicides in decades, with significant drops in cities like Chicago, Memphis, and Portland, Oregon, after peaking in 2022. Our hometown of Baltimore saw homicides drop significantly by “embracing a public health approach to reducing gun violence,” says Joshua Sharfstein, MD, vice dean for Public Health Practice and Community Engagement. Other gun violence prevention efforts also made headway.

And while preventable mass shootings continue to occur with too much frequency, overall they were down in 2025.

Overdose deaths trended down.

National data show a 25% decline in overdose deaths from the year ending in March 2025 compared to the previous year. In Baltimore, a health approach meant that not a single life was lost in two mass overdose events. And innovations like vending machines dispensing free naloxone are expanding access to harm reduction tools—and helping prevent overdoses.

Public Health Issues That Got Us Talking

Top of our list: Where is AI headed—and how do we harness its power for good? 

Large language models have seemingly limitless potential to both help and hinder public health, and 2026 will be a crucial year for determining how much they do of each. For example, they’re the tools behind the phenomenon of “AI psychosis,” a term that gained traction this year to describe cases where the tools reinforced delusional thinking—sometimes with deadly consequences. They’ve also shown their value, outperforming standard methods for suicide risk screening, and enabling huge analyses of health records that “finally allows us to study the real-world safety and effectiveness of medicinal cannabis at a population scale,” says Johannes Thrul, PhD, MS, an associate professor in Mental Health. 

This is a topic to watch as researchers and the public look to “figure out how to leverage the good parts of generative AI in ways that are safe,” says Emily Haroz, PhD ’15, MHS ’11, MA, an associate professor in International Health. 

“I hope we will see a push for AI safety protocols and evaluations ... and a rising demand for transparency regarding which type of ‘mind’ a vulnerable user is interacting with,” says Thrul. But, notes Haroz, it remains to be seen how calls for tighter AI regulations will stack up against possible executive orders blocking states from regulating AI.

Other questions that defined public health in 2025—and will continue into 2026 and beyond:

• Does Tylenol use during pregnancy cause autism? Existing research suggests that taking acetaminophen during pregnancy does not cause autism in children. But rhetoric discouraging Tylenol use during pregnancy and the difficulty of establishing cause and effect continue to drive debate.
• What will happen with bird flu? Fears about a bird flu pandemic weren’t realized this year. But after a quiet summer, new outbreaks emerged in the fall and bird migrations pose an ongoing threat. New reporting suggests there are flaws in the U.S.’s bird flu playbook.
• What to do about ultra-processed foods? Linked to a host of health issues, these foods make up more than half of the calories consumed by the average American adult—but it’s important to note that UPFs are not all created equal, says Julia Wolfson, PhD ’16, MPP, an associate professor in International Health.
• How dangerous is alcohol? In January, then-Surgeon General Vivek Murthy issued a warning on alcohol and cancer, and researchers pushed for alcohol warning labels. While there’s a “massive cultural shift” toward drinking less, public awareness of alcohol’s harms is still lacking.

Other big discussions this year: The case for introducing allergens early, how to understand a scientific study, and how the concept of One Health can help prevent the next pandemic.

Wins You May Have Missed

Below the fold, there were public health wins that didn’t get as much attention. Bloomberg School faculty shared the ones that stuck with them this year:

“The continued deployment of advanced modalities for treatment and prevention in filovirus outbreaks. For both Ebola and Marburg outbreaks that have occurred in the past year, a concerted effort to use the latest scientific medical countermeasures is becoming standard of care, taming these outbreaks and improving the individual lives of those infected.” —Amesh Adalja, MD, senior scholar at the Center for Health Security

“In type 2 diabetes, big wins have been the focus on new medications like SGLT2 inhibitors and GLP1-RAs, which reduce the risk of heart and kidney disease. In type 1 diabetes, we saw the first islet cell transplants using a new medication which resulted in patients being able to discontinue insulin injections.” —Elizabeth Selvin, PhD ’04, MPH, professor in Epidemiology

“Brazil became the first country to approve Butantan-DV, the first single-dose dengue vaccine. The Center for Immunization Research, under the leadership of Anna Durbin, did about 30 trials to get this vaccine to the point where it got licensed.” —Kawsar Talaat, MD, associate professor in International Health

The Word of the Year

When asked about the biggest challenge of 2025, our faculty landed on a common theme: trust. Specifically, the erosion of trust in public health and science. 

For David Dowdy, MD, PhD ’08, ScM ’02, professor in Epidemiology, the trust issue has an upside:

“Public health’s biggest victories are often unrecognized—because the prevention or control of a health crisis doesn’t make headlines. But at the end of the day, science produces results, and results build trust. 

“I think 2025 has been a victory for public health science—because trust in public health has been challenged like never before, and public health scientists have responded by sticking to the science and continuing to produce results that are improving the health of our country and our world.”