Gaultier GN, et al. - Among chronic kidney disease (CKD) (n=60) residents of a geographic region with a noticeable presence of Haemophilus influenzae type a (Hia) invasive disease, researchers assessed natural immunity against Hia and B-cell subpopulations so that the response to Hia immunization among immunocompromised Indigenous adults could be predicted. This study also included 35 healthy controls of the same age. Indigenous vs non-Indigenous patients had higher IgM antibody levels. A higher proportion of B cells (CD19+), class switched memory B cells (CD19+CD27+IgM-) and a lower proportion of CD19+CD27-IgM- B cells was seen in CKD patients vs healthy controls. Significantly higher proportions of IgM memory B cells and CD19+CD27-IgM- B cells were detected among non-Indigenous patients with CKD vs Indigenous patients with no significant variation in absolute numbers. Because re-activation of immunological memory against Hia could be potentially induced by a Hia-conjugate vaccine, this vaccine may be immunogenic in adult patients with CKD.