SARS-CoV-2, the coronavirus responsible for the current COVID-19 pandemic, is also a threat to our closest living relatives, the great apes. As leading experts in the conservation and health of these animals, we urge governments, conservation practitioners, researchers, tourism professionals and funding agencies to reduce the risk of introducing the virus into these endangered apes. They can do this by applying the International Union for Conservation of Nature’s best-practice guidelines for health monitoring and disease control in great-ape populations (see go.nature.com/3b1bq9k).

It is unknown whether the morbidity and mortality associated with SARS-CoV-2 in humans are similar in apes. However, transmission of even mild human pathogens to apes can lead to moderate-to-severe outcomes (L. V. Patrono et al. Emerg. Microbes Infect. 7, 1–4; 2018).

In the present situation, we recommend that great-ape tourism be suspended and field research reduced, subject to risk assessments to maximize conservation outcomes (for example, poaching could rise with fewer people in the vicinity). Such efforts should include ways to offset loss of earnings from tourism, while taking care not to interfere with work to save human lives.