In countries with high levels of poverty or instability and with poor health system management and governance, people are highly vulnerable to shocks associated with ill health, including major epidemics. An effective health system can help build their resilience by reducing exposure to infection and minimising the impact of sickness on livelihoods and economic development. There is broad consensus on the key elements of such a health system: measures to protect public health, access to safe and effective basic health services, hospital back-up and a capacity to respond to major health shocks. The creation of such systems requires sustained efforts to strengthen state oversight of the health sector and to build effective partnerships for public health and service delivery. Managing the crisis response should include anticipating the need to build effective, trusted health systems that meet priority needs.