On the Horizon: Looking Back and Looking Ahead

2025 will be remembered as one of global health’s most fragile years. It started with the U.S.’s withdrawal from the World Health Organization, despite historically being its largest donor, part of a cascade of budget cuts across international health programs. Not long after, USAID was shuttered, abruptly cutting off vital funds that the world’s most vulnerable countries depend on to support health programs. 

The ripple effects were immediate and severe. Countries that had made steady progress toward immunization goals suddenly faced resource shortages. Health workers in fragile settings worried about the sustainability of lifesaving programs. A global health architecture that took decades to build teetered on uncertain ground. 

But the global immunization community refused to retreat. 

In December, global leaders gathered in Abu Dhabi to pledge $1.9 billion for polio eradication, including approximately $1.2 billion in newly committed funds. This show of solidarity came on the heels of funding anxiety for the Global Polio Eradication Initiative’s 2022-2029 Strategy, bringing the resource gap down to just $440 million.  

These funds will accelerate efforts to reach 370 million children each year with polio vaccines, while also strengthening health systems to protect against other preventable diseases. For example, the Democratic Republic of the Congo recently declared the end of its year-long Ebola outbreak, demonstrating how polio eradication infrastructure can be leveraged when responding to other health emergencies.  

The duality of our fight against measles has never been more stark than in 2025. WHO reported that since 2000, nearly 59 million lives have been saved by the measles vaccine, with deaths falling by 88% since then. Interestingly, 2024 saw falling measles deaths paired with rising measles outbreaks, meaning that middle- and upper-income countries with the facilities to treat an infection are seeing far more cases than normal. 

It’s hard to have missed the headlines about surging measles cases worldwide in 2025, a sobering reminder that progress is not permanent. Declining vaccination rates, driven by instability, misinformation, and disrupted health services, allowed the most contagious disease to gain ground in communities that has previously been protected—including here in the U.S. 

Despite the disruptions, critical global health infrastructure was reinforced in some spots through 2025. After three years of negotiations, WHO member states signed a historic pandemic agreement, paving the way for improved pandemic prevention and response. Strengthened disease surveillance and better global access to vaccines and treatments play a critical role.  

While the U.S. did not sign on, the agreement still represents a significant step to preventing future pandemics. And America’s stake in global health has not been abandoned entirely.  

In fact, as of early January 2026, over a dozen bilateral health cooperation agreements have been solidified by State Department. The America First Global Health Strategy’s continuity with longstanding global health priorities—including explicit goals for polio eradication, addressing tuberculosis, and malaria prevention—is encouraging. But with the health assistance lens shifting to emphasize U.S. trade and security interests over development concerns, there are undoubtedly ramifications that may be yet to be seen. 

As we enter the new year, several challenges and opportunities lie on the horizon. 

It’s no secret that 2025’s funding disruptions created large resource gaps for global health. The Global Fund to Fight AIDS, Tuberculosis, and Malaria raised an impressive $11.34 billion at its Eighth Replenishment Summit, demonstrating strong commitment from countries, the private sector, and philanthropies. However, more pledges are needed to unlock the full potential of existing matching commitments and protect millions of lives. 

Organizations like Gavi, the Vaccine Alliance, are adapting to this new reality. In a major strategic shift, 90% of Gavi’s vaccine procurement budget will be for recipient countries to make distribution decisions. In keeping with the U.S. push for greater autonomy, this model allows countries to individually optimize and prioritize immunization programs in their national context, while also giving an advance view of available resources. And, despite overall budget constraints, Gavi’s Board increased support for fragile and conflict-affected settings by 15% compared to the previous strategic period.  

The lessons learned from polio vaccination campaigns in Gaza and South Sudan—where teams reached hundreds of thousands of children amid active conflict—also provide blueprints going forward.  

The global immunization community must double down on efforts to reach children affected by conflict, displacement, and humanitarian crises. And disease surges in these settings are accompanied by reminders much closer to home of the importance of vaccination: Europe and the U.S. are both experiencing intense surges of influenza, with at least 27 of 38 European countries seeing spiked activity. This surge—in addition to that of other diseases, like measles—highlights the importance of seasonal vaccination campaigns. As health policy experts note, immunization should be treated as an economic imperative, not just a health intervention, especially for diseases like RSV and pneumococcal infections that strain healthcare systems and economies.  

The vaccine development pipeline heading into 2026 offers remarkable promise in the fight against diseases that have long eluded effective prevention. 

#1) Dengue: The Time is Now 

The fight against dengue saw significant progress in late 2025, with multiple vaccine candidates advancing. Brazil approved the Butantan-DV vaccines—the world’s first single-dose dengue vaccine—which will be incorporated into Brazil’s national immunization program early this year. In clinical trials, the vaccine showed an impressive 91.6% efficacy against severe dengue, with 100% effectiveness in preventing hospitalizations. The vaccine will be incorporated into Brazil’s national immunization program in 2026. Dengue cases surged to over 14 million in 2024, with the Amazon hit particularly hard—meaning that Brazil’s innovation could not come at a better time.  

#2) Tuberculosis: A Century-Long Wait May Finally End 

Perhaps the most anticipated breakthrough is the M72/AS01E tuberculosis vaccine, which could become the first new TB vaccine in more than a century. A landmark Phase 3 clinical trial is now underway, having enrolled 20,000 people across sites in South Africa, Kenya, Zambia, and Indonesia. The vaccine has also shown an acceptable safety profile in people living with HIV, which is critical given that TB is the leading cause of death among people with HIV. Results from the current Phase 3 trial are expected this year or the next and, if successful, the WHO estimates it could prevent 76 million new TB cases and save $41.5 billion for TB-affected households over the 25 years. 

As TB claimed 1.23 million lives in 2024, making it once again the world’s deadliest infectious disease, this vaccine candidate represents a potential turning point. 

#3) Beyond Infectious Diseases: Overdose Prevention and Cancer Treatment 

The field of therapeutic cancer vaccines also continues to advance. A first in-human clinical trial of WDVAX, a biomaterial-based cancer vaccine for metastatic melanoma, demonstrated feasibility and safety in patients. Additionally, DNA cancer vaccines are moving into mid to late-stage testing, with Inovio Pharmaceuticals’ HPV-associated cervical cancer candidate and IMUNON’s ovarian cancer vaccine showing promising results in Phase 2 trials.  

And as a bonus—because vaccines never fail to amaze us—the immunization landscape is expanding into new territory. A groundbreaking fentanyl vaccine is entering Phase 1 human trials in early 2026 in the Netherlands. If successful, this would become the first proactive treatment for opioid overdose prevention. The vaccine works by creating antibodies that block fentanyl from crossing the blood-brain barrier, preventing its effects and stopping overdoses before they occur—a fundamentally different approach from reactive treatments like naloxone. 

Put simply: a miracle of science. 

We must acknowledge the difficult realities ahead. Decreasing funding, rising humanitarian crises, and rapidly spreading misinformation are not abstract challenges. They translate to real children, families, and communities who will suffer preventable loss—not just overseas, but right here at home.  

But the global immunization community remains deeply committed—from Abu Dhabi to the Amazon, from researchers to policymakers. The decisions made in 2026 can change the trajectory of global public health and reverberate for years to come. The work is urgent, the need is great, and the time to act is now.