The COVID-19 pandemic has inflicted multifaceted disruptions to routine immunisation from global to local levels, affecting every aspect of vaccine supply, access, and demand. Since March 2020, country programmes have implemented a range of strategies to either continue vaccination services during COVID-19 measures like 'lockdown' and/or resume services when risks of SARS-CoV-2 transmission could be appropriately mitigated. Through the Exemplars in Global Health partnership in Liberia, Nepal, and Senegal, we conducted interviews with immunisation programme managers and ministry of health leadership to better understand how they have addressed the myriad vaccination challenges posed by the ongoing pandemic. From establishing alternative modes of service delivery to combatting vaccine distrust and rumours via risk communication campaigns, many routine immunisation programmes have demonstrated how to adapt, resume, and/or maintain vital vaccination efforts during the COVID-19 crisis. Yet millions of children remain un- or under-vaccinated worldwide, and the same programmes striving to implement catch-up services for missed doses and postponed mass campaigns will also soon be tasked with COVID-19 vaccine deployment. As laid bare by the current pandemic, the world's gains against vaccine-preventable diseases are fragile: enshrined by a delicate global ecosystem of logistics, supply, and procurement, the success of routine immunisation ultimately rests upon dedicated programme staff, the resources and support available to them, and then the trust in and demand for vaccines by their recipients. Our collective lessons learned during COVID-19 offer insights in programme adaptation and resilience that, if prioritised, could strengthen equitable, sustainable vaccine delivery for all populations.