There are many similarities between the immune system and health systems. Both are knowledge-based learning systems with an ultimate common objective of maintaining the health of individuals and populations, respectively. The immune system learns from the environment, and knowledge and discovery are key drivers of health systems improvement and improving health status. But discovery goes well beyond immunology, virology and genomics, for example, in the quest to develop new drugs, vaccines and diagnostic tests. New ways must also be discovered to make sure that these products reach the people who need it most. We must discover ways for knowledge to be turned into effective policies, to inform the practice of healthcare and to inform the public and society at large. Only if discovery is seen in its broadest perspective will we be able to reach the goal of health for all.