D Githang'a1, R N Wangia2, M W Mureithi3, S O Wandiga4, C Mutegi5, B Ogutu6, A Agweyu7, J-S Wang2, O Anzala3. 1. KAVI - Institute of Clinical Research, University of Nairobi, Kenya; Department of Medical Microbiology, School of Medicine, College of Health Sciences, University of Nairobi, Kenya. Electronic address: davidgithanga@gmail.com. 2. Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602, United States. 3. KAVI - Institute of Clinical Research, University of Nairobi, Kenya; Department of Medical Microbiology, School of Medicine, College of Health Sciences, University of Nairobi, Kenya. 4. Department of Chemistry, College of Biological and Physical Sciences, University of Nairobi, Kenya. 5. International Institute of Tropical Agriculture [IITA], P.O BOX 30772-00100, Nigeria. 6. Centre for Clinical Research-Kenya Medical Research Institute, Kenya. 7. KEMRI-Wellcome Trust Research Programme, P.O. Box 43640 - 00100, Nairobi, Kenya.
Abstract
BACKGROUND: Globally, approximately three million children die each year from vaccine preventable infectious diseases mainly in developing countries. Despite the success of the expanded immunization program, not all infants and children around the world develop the same protective immune response to the same vaccine. A vaccine must induce a response over the basal immune response that may be driven by population-specific, environmental or socio-economic factors. Mycotoxins like aflatoxins are immune suppressants that are confirmed to interfere with both cell-mediated and acquired immunity. The mechanism of aflatoxin toxicity is through the binding of the bio-activated AFB1-8, 9-epoxide to cellular macromolecules. METHODS: We studied Hepatitis B surface antibodies [anti-HBs] levels to explore the immune modulation effects of dietary exposure to aflatoxins in children aged between one and fourteen years in Kenya. Hepatitis B vaccine was introduced for routine administration for Kenyan infants in November 2001. To assess the effects of aflatoxin on immunogenicity of childhood vaccines Aflatoxin B1-lysine in blood serum samples were determined using High Performance Liquid Chromatography with Fluorescence detection while anti-HBs were measured using Bio-ELISA anti-HBs kit. RESULTS: The mean ± SD of AFB1-lysine adducts in our study population was 45.38 ± 87.03 pg/mg of albumin while the geometric mean was 20.40 pg/mg. The distribution of AFB1-lysine adducts was skewed to the right. Only 98/205 (47.8%) of the study population tested positive for Hepatitis B surface antibodies. From regression analysis, we noted that for every unit rise in serum aflatoxin level, anti-HBs dropped by 0.91 mIU/ml (-0.9110038; 95% C.I -1.604948, -0.21706). CONCLUSION: Despite high coverage of routine immunization, less than half of the study population had developed immunity to HepB. Exposure to aflatoxin was high and weakly associated with low anti-HBs antibodies. These findings highlight a potentially significant role for environmental factors that may contribute to vaccine effectiveness warranting further research.
BACKGROUND: Globally, approximately three million children die each year from vaccine preventable infectious diseases mainly in developing countries. Despite the success of the expanded immunization program, not all infants and children around the world develop the same protective immune response to the same vaccine. A vaccine must induce a response over the basal immune response that may be driven by population-specific, environmental or socio-economic factors. Mycotoxins like aflatoxins are immune suppressants that are confirmed to interfere with both cell-mediated and acquired immunity. The mechanism of aflatoxin toxicity is through the binding of the bio-activated AFB1-8, 9-epoxide to cellular macromolecules. METHODS: We studied Hepatitis B surface antibodies [anti-HBs] levels to explore the immune modulation effects of dietary exposure to aflatoxins in children aged between one and fourteen years in Kenya. Hepatitis B vaccine was introduced for routine administration for Kenyan infants in November 2001. To assess the effects of aflatoxin on immunogenicity of childhood vaccines Aflatoxin B1-lysine in blood serum samples were determined using High Performance Liquid Chromatography with Fluorescence detection while anti-HBs were measured using Bio-ELISA anti-HBs kit. RESULTS: The mean ± SD of AFB1-lysine adducts in our study population was 45.38 ± 87.03 pg/mg of albumin while the geometric mean was 20.40 pg/mg. The distribution of AFB1-lysine adducts was skewed to the right. Only 98/205 (47.8%) of the study population tested positive for Hepatitis B surface antibodies. From regression analysis, we noted that for every unit rise in serum aflatoxin level, anti-HBs dropped by 0.91 mIU/ml (-0.9110038; 95% C.I -1.604948, -0.21706). CONCLUSION: Despite high coverage of routine immunization, less than half of the study population had developed immunity to HepB. Exposure to aflatoxin was high and weakly associated with low anti-HBs antibodies. These findings highlight a potentially significant role for environmental factors that may contribute to vaccine effectiveness warranting further research.
Authors: Ellen E Yard; Johnni H Daniel; Lauren S Lewis; Michael E Rybak; Ekaterina M Paliakov; Andrea A Kim; Joel M Montgomery; Rebecca Bunnell; Mamo Umuro Abudo; Willis Akhwale; Robert F Breiman; Shahnaaz K Sharif Journal: Food Addit Contam Part A Chem Anal Control Expo Risk Assess Date: 2013-06-14
Authors: Hifza Rasheed; Ya Xu; Martin E Kimanya; Xiaoxi Pan; Zhihua Li; Xiaobo Zou; Candida P Shirima; Melvin Holmes; Michael N Routledge; Yun Yun Gong Journal: Sci Rep Date: 2021-01-15 Impact factor: 4.379