From outbreak response to system strengthening: preventing diphtheria in Somalia.
Abdullahi Zakaria Abdi ZA, Derow Ismail Mohamud IM, Yusuf Abdi Wahab Salad AWS, Abdi Aniso Mohamed AM et al.
Diphtheria, a vaccine-preventable disease, has re-emerged as a significant public health concern in Somalia, highlighting persistent weaknesses in immunization systems. Recent outbreaks demonstrate that transmission is driven not by limitations of available vaccines but by immunity gaps associated with low routine immunization coverage, high numbers of zero-dose children, conflict, population displacement, and barriers to accessing health services. The 2025 diphtheria outbreak, characterized by substantial morbidity and mortality among children, underscores the urgent need to move beyond reactive outbreak response toward sustainable immunization-system strengthening. This letter emphasizes the importance of improving routine immunization services, expanding catch-up vaccination, strengthening disease surveillance, enhancing vaccine supply chains and cold-chain capacity, and improving immunization data systems for identifying missed populations. Evidence from Somalia's recent vaccination initiatives demonstrates that community-centered approaches, digital tools, and locally adapted outreach strategies can successfully reach underserved groups even in fragile settings. Building resilient immunization systems requires coordinated efforts among government institutions, communities, health workers, and international partners. Strengthening equitable vaccination delivery is essential not only for preventing future diphtheria outbreaks, but also for improving Somalia's preparedness against other vaccine-preventable diseases and future public health emergencies.