Correction to: Nature Microbiology https://doi.org/10.1038/s41564-017-0076-4, published online 4 December 2018.

In the version of this Letter originally published, the x axis labels associated with the left and middle bars in Fig. 4d were inadvertently switched; the labels should have read “Unimmunized (n = 4)” and “Immunized with typhoid toxoid (n = 9)”, respectively. This has now been amended.