Polio Eradication Status 2024: Endemic Countries, Challenges, and Progress

Wild poliovirus (WPV) transmission has been interrupted in most of the world. As of 2024, the Global Polio Eradication Initiative (GPEI) reports:

Current Endemic Countries (WPV1)

• Afghanistan and Pakistan — last two countries with indigenous WPV1 circulation.
• Nigeria was removed from endemic list in 2020 after 3 years without WPV; continues intensive surveillance.

Circulating Vaccine-Derived Poliovirus (cVDPV)

• Oral polio vaccine (OPV) contains live attenuated virus. In under-immunized populations, it can revert to neurovirulence and circulate (cVDPV).
• cVDPV2 is the most common; outbreaks in Africa (DRC, Nigeria, Yemen), Southeast Asia, Israel, UK, USA (NY wastewater 2022).
• Novel OPV type 2 (nOPV2) — more genetically stable — deployed since 2021 to stop cVDPV2 outbreaks.

Eradication Strategy (GPEI 2022–2026)

1. Interrupt WPV1 in Afghanistan/Pakistan (access, trust, cross-border coordination).
2. Stop all cVDPV outbreaks (nOPV2, improved coverage, surveillance).
3. Transition from OPV to IPV (inactivated) globally post-certification.
4. Maintain high immunity, sensitive surveillance (AFP + environmental).

Key Challenges

• Insecurity, vaccine hesitancy, misinformation in endemic zones.
• Suboptimal routine immunization in many countries → cVDPV risk.
• Funding gaps; donor fatigue.
• COVID-19 disruption to campaigns and surveillance.

Why It Matters

Polio causes irreversible paralysis (1 in 200 infections). Eradication saves ~$40–50 billion by 2035 vs. perpetual control. A polio-free world is achievable but requires sustained commitment.