Dobaño, C.Sanz, H.Sorgho, H.Dosoo, D.Mpina, M.Ubillos, I.Aguilar, R.Ford, T.Díez-Padrisa, N.Williams, N.A.Ayestaran, A.et.al.2019-05-272019-05-272019-05doi: 10.1038/s41467-019-10195-zhttp://ugspace.ug.edu.gh/handle/123456789/30285RTS,S/AS01E has been tested in a phase 3 malaria vaccine study with partial efficacy in African children and infants. In a cohort of 1028 subjects from one low (Bagomoyo) and two high (Nanoro, Kintampo) malaria transmission sites, we analysed IgG plasma/serum concentration and avidity to CSP (NANP-repeat and C-terminal domains) after a 3-dose vaccination against time to clinical malaria events during 12-months. Here we report that RTS,S/AS01E induces substantial increases in IgG levels from pre- to post-vaccination (p < 0.001), higher in NANP than C-terminus (2855 vs 1297 proportional change between means), and higher concentrations and avidities in children than infants (p < 0.001). Baseline CSP IgG levels are elevated in malaria cases than controls (p < 0.001). Both, IgG magnitude to NANP (hazard ratio [95% confidence interval] 0.61 [0.48–0.76]) and avidity to C-terminus (0.07 [0.05–0.90]) post-vaccination are significantly associated with vaccine efficacy. IgG avidity to the C-terminus emerges as a significant contributor to RTS,S/AS01E-mediated protection.enImmunologyInfectious diseasesVaccinesMicrobiologyArticle