Summary box The COVID-19 pandemic has disrupted routine and campaign-based vaccination, potentially increasing the future vaccine-preventable disease burden and threatening to overwhelm health systems. Vaccine-preventable diseases are transboundary problems that require global cooperation to achieve the best outcomes. Investments, predominantly by rich countries—in effect transfers to poor countries—are required as part of the financing solution. Theoretical advances show how such funds can be operationally prioritised and disbursed equitably. Such transfers are also in the interest of high-income countries, and cooperation achieves better outcomes than strategies such as travel restrictions for vaccine-preventable diseases. Similar cooperation and financing issues will arise if and when it is time to distribute a COVID-19 vaccine.