Browsing by Author "Juma E"

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    Lessons learnt from the first controlled human malaria infection study conducted in Nairobi, Kenya.
    (2015-Apr-28) Hodgson SH; Juma E; Salim A; Magiri C; Njenga D; Molyneux S; Njuguna P; Awuondo K; Lowe B; Billingsley PF; Cole AO; Ogwang C; Osier F; Chilengi R; Hoffman SL; Draper SJ; Ogutu B; Marsh K; Sanaria Inc, Rockville, MD, USA. shoffman@sanaria.com.; Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya. omandi.cole@gmail.com.; Kenya Medical Research Institute - Wellcome Trust, Centre for Geographical Medical Research (Coast), Kilifi, Kenya. COgwang@kemri-wellcome.org.; Kenya Medical Research Institute - Wellcome Trust, Centre for Geographical Medical Research (Coast), Kilifi, Kenya. blowe@kemri-wellcome.org.; Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya. bernhards.ogutu@indepth-network.org.; Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya. eajuma@kemri.org.; The Jenner Institute, University of Oxford, Oxford, UK. simon.draper@ndm.ox.ac.uk.; Kenya Medical Research Institute - Wellcome Trust, Centre for Geographical Medical Research (Coast), Kilifi, Kenya. patwnju@yahoo.co.uk.; Sanaria Inc, Rockville, MD, USA. pbillingsley@sanaria.com.; Centre for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya. eajuma@kemri.org.; Centre for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya. omandi.cole@gmail.com.; Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya. charles.magiri@usamru-k.org.; Centre for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya. bernhards.ogutu@indepth-network.org.; Kenya Medical Research Institute - Wellcome Trust, Centre for Geographical Medical Research (Coast), Kilifi, Kenya. fosier@kemri-wellcome.org.; The Jenner Institute, University of Oxford, Oxford, UK. Susanne.hodgson@ndm.ox.ac.uk.; Kenya Medical Research Institute - Wellcome Trust, Centre for Geographical Medical Research (Coast), Kilifi, Kenya. smolyneux@kemri-wellcome.org.; Kenya Medical Research Institute - Wellcome Trust, Centre for Geographical Medical Research (Coast), Kilifi, Kenya. asalim@kemri-wellcome.org.; Kenya Medical Research Institute - Wellcome Trust, Centre for Geographical Medical Research (Coast), Kilifi, Kenya. kevin.marsh@ndm.ox.ac.uk.; Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya. danielnjengah@yahoo.com.; Kenya Medical Research Institute - Wellcome Trust, Centre for Geographical Medical Research (Coast), Kilifi, Kenya. kawuondo@kemri-wellcome.org.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. Roma.Chilengi@cidrz.org.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
    BACKGROUND: Controlled human malaria infection (CHMI) studies, in which healthy volunteers are infected with Plasmodium falciparum to assess the efficacy of novel malaria vaccines and drugs, have become a vital tool to accelerate vaccine and drug development. CHMI studies provide a cost-effective and expeditious way to circumvent the use of large-scale field efficacy studies to deselect intervention candidates. However, to date few modern CHMI studies have been performed in malaria-endemic countries. METHODS: An open-label, randomized pilot CHMI study was conducted using aseptic, purified, cryopreserved, infectious P. falciparum sporozoites (SPZ) (Sanaria® PfSPZ Challenge) administered intramuscularly (IM) to healthy Kenyan adults (n = 28) with varying degrees of prior exposure to P. falciparum. The purpose of the study was to establish the PfSPZ Challenge CHMI model in a Kenyan setting with the aim of increasing the international capacity for efficacy testing of malaria vaccines and drugs, and allowing earlier assessment of efficacy in a population for which interventions are being developed. This was part of the EDCTP-funded capacity development of the CHMI platform in Africa. DISCUSSION: This paper discusses in detail lessons learnt from conducting the first CHMI study in Kenya. Issues pertinent to the African setting, including community sensitization, consent and recruitment are considered. Detailed reasoning regarding the study design (for example, dose and route of administration of PfSPZ Challenge, criteria for grouping volunteers according to prior exposure to malaria and duration of follow-up post CHMI) are given and changes other centres may want to consider for future studies are suggested. CONCLUSIONS: Performing CHMI studies in an African setting presents unique but surmountable challenges and offers great opportunity for acceleration of malaria vaccine and drug development. The reflections in this paper aim to aid other centres and partners intending to use the CHMI model in Africa.
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    Trends in uptake and impact of thermostable vaccines in Africa.
    (2025) Kitui SK; Juma E; Ndalama MT; Chilot D; Tolossa D; Woldemedhin B; Muzazu SGY; Digamo K; Mungania J; Manyazewal T; Kenya National Public Health Laboratories-National Influenza Center, Nairobi, Kenya.; Kotebe Metropolitan University, Addis Ababa, Ethiopia.; Center for Innovative Drug Development and Therapeutic Trials for Africa (CDT-Africa), College of Health Sciences, Addis Ababa University, P. O. Box 9086, Addis Ababa, Ethiopia.; Wachemo University, Hossana, Ethiopia.; Kenyatta University, Nairobi, Kenya.; Kenya Veterinary Vaccines Production Institute, Nairobi, Kenya.; Center for Innovative Drug Development and Therapeutic Trials for Africa (CDT-Africa), College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.; University of Gondar, Gondar, Ethiopia.; Enteric Diseases and Vaccines Research Unit, Centre for Infectious Diseases Research in Zambia (CIDRZ), Lusaka, Zambia.; Shenen Gibe General Hospital, Jimma, Ethiopia.
    Vaccination in Africa faces significant challenges due to inadequate cold chain infrastructure, particularly in regions lacking reliable electricity. Approximately 80% of prequalified vaccines require cold chain systems to maintain their potency, which is often unfeasible in remote areas. Exposure to extreme temperatures can lead to a loss of vaccine potency, making it crucial to explore alternatives. Thermostable vaccines represent a technological advancement that addresses these challenges by eliminating the need for cold chain mechanisms during transport and storage. This narrative review analyzes trends in the uptake of thermostable vaccines and their impact across Africa. A total of 10 studies were reviewed, encompassing 14 African countries, revealing critical insights into the potential of thermostable vaccines to enhance immunization coverage in settings with limited access to traditional cold chain facilities. These vaccines, which maintain their efficacy even when exposed to higher temperatures for short periods, offer a promising solution to the logistical and economic hurdles of vaccine delivery in resource-limited settings.