Nature 517, 89–93 (2015); doi:10.1038/nature13801

In this Letter, author J.-L.C. was inadvertently missing one of their affiliations; they should also have been associated with affiliation number 2 (St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, New York 10065, USA). This has been corrected in the online versions of the paper.