The international public health community was hopeful that polio—the crippling viral illness that previously paralyzed hundreds of thousands of children every year—was almost extinct. But in a concerning twist in 2025, the World Health Organization (WHO) has raised the alarm- polio is back, and eradication hangs in the balance.In 2020, the world celebrated a milestone—polio was officially eradicated everywhere except two nations. But in the first quarter of 2025, an old nemesis has reappeared. Cases of wild poliovirus are again increasing in Pakistan and Afghanistan, the final two bastions of endemic transmission. Pakistan, which had reported 74 cases in 2024, has already seen 6 new cases this year. Afghanistan is not far behind with 1 reported case.While the numbers are small in themselves, they portend a worrisome trend in a decades-long fight. Global health professionals point to interruptions of vaccine campaigns—interruptions they say are directly caused by deep reductions in international assistance.One major factor behind this upsurge is the abrupt interruption of funding support from the United States Agency for International Development (USAID). USAID has long been a pillar of support for vaccination activities in polio-endemic and high-risk areas by financing personnel, logistics, vaccine sourcing, and outreach.A private memo by Nicholas Enrich, USAID acting assistant administrator for global health, cautions that if these pauses in funding continue, we will witness another 200,000 cases of polio paralysis each year, and hundreds of millions more are at risk of being infected. The International Rescue Committee (IRC), which was carrying out polio vaccinations under the watch of the Ministry of Health and World Vision in Kenya, says its USAID-funded program was the initial one to close on January 31st."Right now, IRC support for polio immunization in Kenya's hard-to-reach areas has come to a halt," confirms Mohamed El Montassir Hussein, Kenya's IRC country director. Although local health officials are still immunizing, their efforts are strained without foreign funding.Why Does Wild Polio Persist in Just Two Countries?Pakistan and Afghanistan are the exceptions to an otherwise polio-free world. Several chronic challenges, according to experts, include unstable security environments, misinformation, religious and political opposition to vaccination, and weak health infrastructures. Additionally, vaccination teams working in war zones frequently encounter logistical challenges and safety threats.The virus has been extremely resilient. It takes advantage of holes in immunity caused by lack of vaccinations. Adding to the problem is the presence of circulating vaccine-derived poliovirus (cVDPV)—an uncommon event whereby the attenuated virus contained within oral polio vaccines changes and becomes virulent again.WHO Flags High-Risk Nations and Rising Global ConcernThe WHO has listed five countries with the immediate risk of the international spread of polio:AfghanistanPakistanMozambiqueDemocratic Republic of CongoGuineaFurthermore, 35 nations have recorded imported cases of cVDPV type 2, while 10 countries continue to experience active circulation of wild-type or vaccine-derived poliovirus in the last 24 months. WHO's guidelines are:Improved vaccine coverageIncreased access to healthcare in risk areasTravel restrictions for unvaccinated travelers from high-risk areasBut with more than $200 million in donor funding lost— including life-saving funds from the U.S. President's Emergency Plan for AIDS Relief (PEPFAR)—these guidelines encounter tremendous implementation challenges.Hidden Cost of Underfunding Global HealthIt is the invisible spread that makes the situation more threatening. Those countries with weak surveillance systems may not see early outbreaks until it becomes too late. In politically unstable or humanitarian crisis-affected areas, the virus can spread quietly among unvaccinated groups, only to spill over borders.Polio flourishes in these crevices—between the unvaccinated, the untracked, and the neglected. And once it establishes itself, retaking control is that much harder and costly.Although the numbers as they stand are alarming, they also create an opportunity for recommitment on a global scale. Global polio eradication has always been a collective endeavor. Today, more than ever, a concerted effort is needed.WHO Director-General Dr. Tedros Adhanom Ghebreyesus reacted with strong concern over the diminishing U.S. support and asserted the urgency for international collaboration. "The precipitous cuts to U.S. funding also affect efforts to stop polio for good," he cautioned.Relaunching public confidence in vaccines, maintaining secure access during times of conflict, reinstating funds channels, and reinforcing surveillance form part of the arsenal necessary to complete the mission against polio.The resurgence of polio in 2025 is a wake-up call. It reminds the world that public health victories, no matter how close, can unravel quickly without consistent investment and collaboration.Eradiating polio was never a matter of one country or one continent. It was about a shared global commitment. If the trend continues, we will risk wasting decades of progress—and allowing a preventable disease to reassert its hold on the world's most vulnerable.