What Happened to Polio (Disease Eradication Efforts)?

The global campaign to eradicate polio, a debilitating and often fatal disease, represents one of humanity's most ambitious public health undertakings. Initiated in 1988 with the launch of the Global Polio Eradication Initiative (GPEI) by the World Health Organization (WHO), Rotary International, UNICEF, and the U.S. Centers for Disease Control and Prevention (CDC), the effort built upon the success of effective vaccines developed in the 1950s and 1960s by Jonas Salk (inactivated polio vaccine, IPV) and Albert Sabin (oral polio vaccine, OPV). At its inception, polio paralyzed over 1,000 children daily across 125 countries.

The remarkable progress achieved is a testament to sustained international cooperation and mass vaccination campaigns, which have immunized over 2.5 billion children. Key turning points include the certification of the Americas as polio-free in 1994, followed by the Western Pacific Region in 2000, India in 2014, and the entire African Region in 2020. Furthermore, two of the three wild poliovirus strains have been globally eradicated: type 2 in 2015 and type 3 in 2019. This success has prevented an estimated 20 million cases of paralysis and saved countless lives.

However, the final stretch of eradication has proven exceptionally challenging. As of July 2026, wild poliovirus type 1 (WPV1) remains endemic in only two countries: Afghanistan and Pakistan. These nations face unique obstacles, including ongoing conflict, insecurity, difficult terrain, mobile populations, and, in some areas, vaccine refusals fueled by misinformation and distrust. The porous border between Afghanistan and Pakistan facilitates cross-border transmission, making coordinated efforts crucial. In 2024, there was a significant increase in WPV1 cases in both countries, with 99 cases reported globally, compared to 40 in 2025 and 14 cases reported across both countries as of July 2026 (11 in Afghanistan, 3 in Pakistan).

A growing concern is the rise of circulating vaccine-derived poliovirus (cVDPV), particularly type 2 (cVDPV2). These outbreaks occur when the weakened live virus in the oral polio vaccine circulates in under-immunized populations, mutates, and regains its ability to cause paralysis. In 2025, 202 cVDPV cases were reported globally across 27 countries, with 192 being cVDPV2. By March 2026, the CDC issued a global polio travel advisory, listing over 30 countries where polio is circulating, including detections of VDPV2 in London sewage, indicating ongoing importation risk and declining vaccination coverage in some European areas. The GPEI's 2022-2026 strategy was extended to 2029, with new targets for WPV1 eradication by the end of 2027 and cVDPV2 elimination by the end of 2029, reflecting the complex epidemiological landscape.

Funding remains a critical component. In December 2025, global leaders pledged US$1.9 billion towards the GPEI's extended 2022-2029 strategy, which has a total budget of US$6.9 billion. This funding aims to accelerate vaccination campaigns, strengthen health systems, and integrate polio immunization with other essential health services. Despite the challenges, the GPEI continues to innovate, deploying new vaccination strategies like the novel oral polio vaccine type 2 (nOPV2) and enhancing surveillance capabilities to detect and respond to outbreaks faster. The ultimate goal remains a world where no child ever suffers from polio, a vision that requires sustained commitment and vigilance until every last virus is gone.