Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine
Abstract Background A Phase 1-2b study of the blood stage malaria vaccine AMA1-C1/Alhydrogel was conducted in 336 children in Donéguébougou and Bancoumana, Mali. In the Phase 2 portion of the study (n = 300), no impact on parasite density or clinical malaria was seen; however, children who received...
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ftdoajarticles:oai:doaj.org/article:06ab6b0f1980493dadc24f659746051f 2023-05-15T15:16:50+02:00 Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine Guindo Aldiouma Guindo Merepen A Miura Kazutoyo Dicko Alassane Sagara Issaka Fay Michael P Ellis Ruth D Sissoko Mahamadou S Doumbo Ogobara K Diallo Dapa 2011-01-01T00:00:00Z https://doi.org/10.1186/1475-2875-10-13 https://doaj.org/article/06ab6b0f1980493dadc24f659746051f EN eng BMC http://www.malariajournal.com/content/10/1/13 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-10-13 1475-2875 https://doaj.org/article/06ab6b0f1980493dadc24f659746051f Malaria Journal, Vol 10, Iss 1, p 13 (2011) Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 article 2011 ftdoajarticles https://doi.org/10.1186/1475-2875-10-13 2022-12-30T21:45:36Z Abstract Background A Phase 1-2b study of the blood stage malaria vaccine AMA1-C1/Alhydrogel was conducted in 336 children in Donéguébougou and Bancoumana, Mali. In the Phase 2 portion of the study (n = 300), no impact on parasite density or clinical malaria was seen; however, children who received the study vaccine had a higher frequency of anaemia (defined as haemoglobin < 8.5 g/dL) compared to those who received the comparator vaccine (Hiberix). This effect was one of many tested and was not significant after adjusting for multiple comparisons. Methods To further investigate the possible impact of vaccination on anaemia, additional analyses were conducted including patients from the Phase 1 portion of the study and controlling for baseline haemoglobin, haemoglobin types S or C, alpha-thalassaemia, G6PD deficiency, and age. A multiplicative intensity model was used, which generalizes Cox regression to allow for multiple events. Frailty effects for each subject were used to account for correlation of multiple anaemia events within the same subject. Intensity rates were calculated with reference to calendar time instead of time after randomization in order to account for staggered enrollment and seasonal effects of malaria incidence. Associations of anaemia with anti-AMA1 antibody were further explored using a similar analysis. Results A strong effect of vaccine on the incidence of anaemia (risk ratio [AMA1-C1 to comparator (Hiberix)]= 2.01, 95% confidence interval [1.26,3.20]) was demonstrated even after adjusting for baseline haemoglobin, haemoglobinopathies, and age, and using more sophisticated statistical models. Anti-AMA1 antibody levels were not associated with this effect. Conclusions While these additional analyses show a robust effect of vaccination on anaemia, this is an intensive exploration of secondary results and should, therefore, be interpreted with caution. Possible mechanisms of the apparent adverse effect on haemoglobin of vaccination with AMA1-C1/Alhydrogel and implications for blood ... Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic Malaria Journal 10 1 |
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Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
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Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 Guindo Aldiouma Guindo Merepen A Miura Kazutoyo Dicko Alassane Sagara Issaka Fay Michael P Ellis Ruth D Sissoko Mahamadou S Doumbo Ogobara K Diallo Dapa Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
description |
Abstract Background A Phase 1-2b study of the blood stage malaria vaccine AMA1-C1/Alhydrogel was conducted in 336 children in Donéguébougou and Bancoumana, Mali. In the Phase 2 portion of the study (n = 300), no impact on parasite density or clinical malaria was seen; however, children who received the study vaccine had a higher frequency of anaemia (defined as haemoglobin < 8.5 g/dL) compared to those who received the comparator vaccine (Hiberix). This effect was one of many tested and was not significant after adjusting for multiple comparisons. Methods To further investigate the possible impact of vaccination on anaemia, additional analyses were conducted including patients from the Phase 1 portion of the study and controlling for baseline haemoglobin, haemoglobin types S or C, alpha-thalassaemia, G6PD deficiency, and age. A multiplicative intensity model was used, which generalizes Cox regression to allow for multiple events. Frailty effects for each subject were used to account for correlation of multiple anaemia events within the same subject. Intensity rates were calculated with reference to calendar time instead of time after randomization in order to account for staggered enrollment and seasonal effects of malaria incidence. Associations of anaemia with anti-AMA1 antibody were further explored using a similar analysis. Results A strong effect of vaccine on the incidence of anaemia (risk ratio [AMA1-C1 to comparator (Hiberix)]= 2.01, 95% confidence interval [1.26,3.20]) was demonstrated even after adjusting for baseline haemoglobin, haemoglobinopathies, and age, and using more sophisticated statistical models. Anti-AMA1 antibody levels were not associated with this effect. Conclusions While these additional analyses show a robust effect of vaccination on anaemia, this is an intensive exploration of secondary results and should, therefore, be interpreted with caution. Possible mechanisms of the apparent adverse effect on haemoglobin of vaccination with AMA1-C1/Alhydrogel and implications for blood ... |
format |
Article in Journal/Newspaper |
author |
Guindo Aldiouma Guindo Merepen A Miura Kazutoyo Dicko Alassane Sagara Issaka Fay Michael P Ellis Ruth D Sissoko Mahamadou S Doumbo Ogobara K Diallo Dapa |
author_facet |
Guindo Aldiouma Guindo Merepen A Miura Kazutoyo Dicko Alassane Sagara Issaka Fay Michael P Ellis Ruth D Sissoko Mahamadou S Doumbo Ogobara K Diallo Dapa |
author_sort |
Guindo Aldiouma |
title |
Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine |
title_short |
Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine |
title_full |
Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine |
title_fullStr |
Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine |
title_full_unstemmed |
Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine |
title_sort |
anaemia in a phase 2 study of a blood stage falciparum malaria vaccine |
publisher |
BMC |
publishDate |
2011 |
url |
https://doi.org/10.1186/1475-2875-10-13 https://doaj.org/article/06ab6b0f1980493dadc24f659746051f |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Malaria Journal, Vol 10, Iss 1, p 13 (2011) |
op_relation |
http://www.malariajournal.com/content/10/1/13 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-10-13 1475-2875 https://doaj.org/article/06ab6b0f1980493dadc24f659746051f |
op_doi |
https://doi.org/10.1186/1475-2875-10-13 |
container_title |
Malaria Journal |
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10 |
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1 |
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1766347123104677888 |