Geospatial Variation in Vaccination Coverage and Zero-Dose Prevalence at the District, Ward and Health Facility Levels Before and After a Measles Vaccination Campaign in Nigeria.

Many measles endemic countries with suboptimal coverage levels still rely on vaccination campaigns to fill immunity gaps and boost control efforts. Depending on local epidemiological patterns, national or targeted campaigns are implemented, following which post-campaign coverage surveys (PCCSs) are conducted to evaluate their performance, particularly in terms of reaching previously unvaccinated children. Due to limited resources, PCCS surveys are designed to be representative at coarse spatial scales, often masking important heterogeneities in coverage that could enhance the identification of areas of poor performance for follow-up via routine immunization strategies.

Geospatial Analyses of Recent Household Surveys to Assess Changes in the Distribution of Zero-Dose Children and Their Associated Factors before and during the COVID-19 Pandemic in Nigeria.

The persistence of geographic inequities in vaccination coverage often evidences the presence of zero-dose and missed communities and their vulnerabilities to vaccine-preventable diseases. These inequities were exacerbated in many places during the coronavirus disease 2019 (COVID-19) pandemic, due to severe disruptions to vaccination services. Understanding changes in zero-dose prevalence and its associated risk factors in the context of the COVID-19 pandemic is, therefore, critical to designing effective strategies to reach vulnerable populations.

Root cause analysis underscores the importance of understanding, addressing, and communicating cold chain equipment failures to improve equipment performance.

Vaccine cold chain equipment (CCE) in developing countries is often exposed to harsh environmental conditions, such as extreme temperatures and humidity, and is subject to many additional challenges, including intermittent power supply, insufficient maintenance capacity, and a scarcity of replacement parts. Together, these challenges lead to high failure rates for refrigerators, potentially damaging vaccines and adversely affecting immunization coverage. Providing a sustainable solution for improving CCE performance requires an understanding of the root causes of failure.

Understanding the policy environment for immunization supply chains: Lessons learned from landscape analyses in Uganda and Senegal.

As immunization programs around the world undergo rapid change and expansion, supply chain and logistics systems have become strained, making it increasingly challenging for national public health systems to provide reliable, safe, and efficient access to vaccines. Governments and immunization partners have been aware of this problem for several years, and in 2010, the World Health Organization (WHO) launched the Effective Vaccine Management (EVM) process to help countries identify shortcomings in their immunization supply chains and develop plans for systematic improvement. EVM improvement plans now exist in all Gavi-eligible countries plus many middle- and upper-income countries; however, implementation has been slow and in many cases fraught with financial, managerial, structural, and political roadblocks.