Seven-year kinetics of RTS, S/AS01-induced anti-CSP antibodies in young Kenyan children

Malaria Journal

Faiz M. Shee¹  Juliana Wambua²  Edward Otieno²  Jedidah Mwacharo²  Jennifer N. Musyoki²  Kennedy Mwai²  Philip Bejon³  Robert M. Mugo⁴  Francis M. Ndungu⁵ 

[1] Department of Biological Sciences, Pwani University, P.O. Box 195-80108, Kilifi, Kenya;KEMRI-Wellcome Trust Collaborative Programme, P.O. Box 230, 80108, Kilifi, Kenya;KEMRI-Wellcome Trust Collaborative Programme, P.O. Box 230, 80108, Kilifi, Kenya;Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK;KEMRI-Wellcome Trust Collaborative Programme, P.O. Box 230, 80108, Kilifi, Kenya;Institute of Immunology, Center for Infection Medicine, Freie Universtät Berlin, 14163, Berlin, Germany;Department of Biological Sciences, Pwani University, P.O. Box 195-80108, Kilifi, Kenya;KEMRI-Wellcome Trust Collaborative Programme, P.O. Box 230, 80108, Kilifi, Kenya;Institute of Immunology, Center for Infection Medicine, Freie Universtät Berlin, 14163, Berlin, Germany;Department of Biological Sciences, Pwani University, P.O. Box 195-80108, Kilifi, Kenya;Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK;Division of Infectious Diseases, Department of Medicine Solna and Centre for Molecular Medicine, Karolinska Institute, Stockholm, Sweden;

关键词: RTS,S/AS01;    Vaccines;    Antibodies;    Plasmodium falciparum;    Circumsporozoite protein;   

DOI  :  10.1186/s12936-021-03961-2

来源: Springer

【 摘 要 】

BackgroundRTS,S/AS01, the leading malaria vaccine has been recommended by the WHO for widespread immunization of children at risk. RTS,S/AS01-induced anti-CSP IgG antibodies are associated with the vaccine efficacy. Here, the long-term kinetics of RTS,S/AS01-induced antibodies was investigated.Methods150 participants were randomly selected from the 447 children who participated in the RTS,S/AS01 phase IIb clinical trial in 2007 from Kilifi-Kenya. Cumulatively, the retrospective follow-up period was 93 months with annual plasma samples collection. The levels of anti-CSP IgM, total IgG, IgG1, IgG2, IgG3, and IgG4 antibodies were then determined using an enzyme-linked immunosorbent assay.ResultsRTS,S/AS01 induced high levels of anti-CSP IgG antibodies which exhibited a rapid waning over 6.5 months post-vaccination, followed by a slower decay over the subsequent years. RTS,S/AS01-induced anti-CSP IgG antibodies remained elevated above the control group levels throughout the 7 years follow-up period. The anti-CSP IgG antibodies were mostly IgG1, IgG3, IgG2, and to a lesser extent IgG4. IgG2 predominated in later timepoints. RTS,S/AS01 also induced high levels of anti-CSP IgM antibodies which increased above the control group levels by month 3. The controls exhibited increasing levels of the anti-CSP IgM antibodies which caught up with the RTS,S/AS01 vaccinees levels by month 21. In contrast, there were no measurable anti-CSP IgG antibodies among the controls.ConclusionRTS,S/AS01-induced anti-CSP IgG antibodies kinetics are consistent with long-lived but waning vaccine efficacy. Natural exposure induces anti-CSP IgM antibodies in children, which increases with age, but does not induce substantial levels of anti-CSP IgG antibodies.

【 授权许可】

CC BY