Diphtheria’s global resurgence:
A preventable crisis demanding renewed and continuous vigilance

Diphtheria, once a global scourge, had been relegated to the margins of public health concern in much of the world thanks to decades of successful vaccination campaigns. Yet, in 2025, the disease is making a troubling comeback, exposing gaps in immunization, the fragility of health systems, and the persistent vulnerability of marginalized populations. The current situation underscores the urgent need for sustained vigilance, robust public health infrastructure, and equitable vaccine access.  A preventable disease, yet still deadly  Diphtheria is a bacterial infection caused by Corynebacterium diphtheriae, primarily affecting the upper respiratory tract and sometimes the skin. Its toxin can lead to severe complications, including heart failure and nerve damage, and is often fatal without prompt treatment. The disease is almost entirely preventable through vaccination, yet multiple doses and boosters are required to maintain immunity.  Recent global trends and outbreaks  After years of declining incidence, recent data reveal a sharp resurgence of diphtheria in several regions. In 2023, nearly 25,000 cases were reported...