Strong disease surveillance systems are critical to achieving universal health coverage (UHC), given that they provide governments and public health decision-makers with the data they need to ensure that all people and communities have access to health services. This data is particularly important in the context of infectious disease outbreaks, during which government officials must act quickly and decisively to prevent the spread of disease. Strengthened health systems, management and evaluation approaches, and improved policies can help address critical gaps in national immunization systems.