Most new infectious diseases result from the spillover of pathogens from animals, particularly wildlife, to people. Spillover prevention should not be dismissed in discussions on how best to address pandemics (see Nature 596, 332–335; 2021).
The belief that we are powerless to prevent spillover is, unfortunately, endorsed by many in public health and government. Improved management of farmed animals, regulations on wildlife trade and conservation of tropical forests have all helped to prevent spillover and subsequent outbreaks, as well as boosting greenhouse-gas mitigation and wildlife conservation (see go.nature.com/2uqwx1u). Moreover, preventing spillover is cheap compared with the costs of a single pandemic (A. P. Dobson et al. Science 369, 379–381; 2020).
Outbreak containment measures will always be necessary, especially for the most vulnerable people in resource-limited settings, because spillover can never be completely eliminated. But if prioritized alongside post-spillover initiatives, outcomes will be more cost-effective, scientifically informed and equitable.
