What lessons does the COVID-19 syndemic offer when considering the convergence between health and education? The International Day of Education, on Jan 24, provides an opportunity to reflect on the weaknesses of the education system before COVID-19, and on the impact of school closures and education disruptions on children and adolescents. Since March, 2020, more than 1·5 billion students worldwide—an unprecedented number—have been affected by school or university closures.