The WHO Guide on Oral Cholera Vaccines in Mass Immunization Campaigns provides guidance on the planning and implementation of oral cholera vaccine (OCV) campaigns. It covers key aspects such as when and where to use OCVs, vaccine specifications, and recommendations for use in endemic areas, outbreak settings, and complex emergencies. The document outlines steps for macro- and micro-planning, logistics, budgeting, human resource allocation, and risk communication. It also highlights challenges, including cold chain management, vaccine supply, and community engagement, ensuring that vaccination campaigns are efficient and effective in reducing cholera outbreaks.