The corona crisis has grave consequences for health, the economy and society. Pandemics such as COVID-19, Ebola and cholera will return repeatedly unless we understand what causes them. New infectious diseases in humans are often unleashed by viruses and bacteria in wild animals. The destruction of undisturbed ecosystems brings humans into closer contact with animal species that could transmit hitherto unknown pathogens. Consequently, the only way to successfully prevent localised epidemics and continental pandemics is to view human, animal and environmental health as one unit, as it is in the One Health concept.