This week marked “World Immunization Week” around the world, prompting an outpouring of discussion and ideas about how to help vaccines work for all children. Key challenges to universal immunisation were tackled, including health data and the potential of digital identities, urbanisation and refugees, and the difficulties of reaching rural and nomadic communities.

Many conversations celebrated the life-saving achievements of vaccination, while other delved into the complex world of vaccine hesitancy, a subject to which Science Magazine devoted a whole issue.

The threat of pandemics and the role of vaccines in countering them continued to grab headlines, Save the Children made the compelling case for more immunisation to prevent child deaths from pneumonia, while measles in Australia and meningitis in Nigeria caused concerns.