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Dr
Ernest Wandera Apondi

Kenya

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Project Title

Development and Deployment of Lateral Flow Antigen Test for COVID-19 (CoVAT)

EDCTP Project

TMA2020CDF-3212

EDCTP Program

EDCTP2

EDCTP Project Call

Career Development Fellowship (CDF)

Project Objectives

1. Generate contextualised COVID-19 antigens and monoclonal antibodies for use in lateral flow antigen test. 2. Develop a rapid diagnostic lateral flow antigen (LFA) strip test for COVID-19 for point of care testing.

Study Design

Obervational study

Project Summary

Whereas the Coronavirus Disease 2019 (COVID-19) is no longer a pandemic and with reduced threat to global health and economy, it has grown to be endemic with multiple outbreaks being reported from time to time, in the presence of other circulating respiratory viruses showing overlapping symptoms. Thus, the use of proper diagnostic tools remains key for proper patient management and disease surveillance. The standard test to detect SARS-CoV-2- based on a mainstay reverse transcription polymerase chain reaction (RT-PCR)- requires trained personnel, specific chemical supplies, and expensive instruments that take hours to provide results and are often available only in laboratories that provide routine, centralized services. This limits the number of tests that can be done, especially in low- and middle-income countries (LMICs). Antigen-based tests offer an attractive alternative solution to SARS-CoV-2 testing needs especially for most LMICs. In this regard, we have developed an antigen-based point-of-care test that we envisage to be affordable, easy to use, and will not need skilled personnel, expensive reagents nor machines. We recognize the fact that the quality of antigen used in immunization plays a critical role in determining the precision of mAbs produced for the development of antigen kits. The wheat germ cell free system (WGCFS) offers an excellent alternative to mammalian cell expression for proteins requiring rapid and scalable production. WGCFS has been demonstrated to produce near native and functionally active proteins while negating posttranslational protein modifications that reduce antigenicity. Thus, we leveraged on an innovative high-throughput WGCFS to generate SARS-CoV-2 nucleocapsid (N) antigens derived from locally circulating sequences. Using these antigens, we produced monoclonal antibodies (mAbs) in BALB/c mice. We evaluated the reactivity of these mAbs with recombinant SARS-CoV-2 N antigens and virus infected culture fluid (ICF) derived from SARS-CoV-2 Beta and Omicron variants using indirect and sandwich ELISA assays. Sandwich ELISA was used to screen for mAbs specificity against other respiratory viruses. The mAbs were mounted on LFA strips and the test reliability of the prototype test kits evaluated using recombinant SARS-CoV-2 N antigens and virus ICF from SARS-CoV-2 Beta and Omicron variants, various respiratory virus ICF and archived COVID-19-positive and negative by qPCR nasopharyngeal clinical samples. The mAbs produced displayed robust reactivity to recombinant SARS-CoV-2 N antigens and Beta and Omicron SARS-CoV-2 variant ICF. The mAbs did not show cross-reactivity with other respiratory viruses, indicating specificity with SARS-CoV-2. The prototype LFA test kit was found to be capable of detecting both recombinant SARS-CoV-2 N antigens, the Beta and Omicron SARS-CoV-2 variants in the infected culture supernatants and SARS-CoV-2 in archived nasopharyngeal clinical samples, suggesting its potential in detecting diverse SARS-CoV-2 variants in clinical setting. Of noteworthy, we have applied to the Kenya Industrial Property Institute (KIPI) for a provisional grant of a patent/registration for this innovation. The prototype LFA test kit demonstrates great promise for point-of-care diagnosis of COVID-19, hence can be a useful tool for ramping up COVID-19 testing in resource-constrained settings. Essentially, our development will contribute to the achievement of the Sustainable Development Goal 3 (Ensuring healthy lives and promoting the well-being of all people at all ages), through the development of a point-of-care COVID-19 antigen test to better inform clinical and public health interventions to protect lives from the disease. Essentially, our point-of-care lateral flow antigen test development will boost the decentralization of COVID-19 testing by making the test available in primary healthcare facilities, in community settings, and potentially even at home. Additionally, this venture has strengthened the domestic capacity in diagnostic technology for COVID-19 and other emerging infectious diseases since the prototype could be readily adapted to any other emerging pathogen. https://gitakalab.com/dr-ernest-wanderas-research-work-tma2020cdf-3212/ Profile on EDCTP Alumni Platform URL: https://edctpalumninetwork.org/profile/233

Host Organisation

Department Institution Country
Graduate Studies and Research Mount Kenya University Trust (MKU) KE

Sites

Results & Outcomes

value="value="value="value="value="value="value="value="value="value="value="value="value=data obtained highlight the importance of RVA gastroenteritis in Kenya and reveal a remarkable genotypic diversity of rotavirus strains circulating in the country. Phylogenetic analysis of the Kenyan G8 and P[6] strains provide evidence for the geographic segregation of G8 RVAs in Africa and point to at least two groups of P[6] RVAs circulating in Kenya. The rapid and marked reductions in rotavirus and all-cause AGE hospitalizations after rotavirus vaccine introduction are suggestive of a significant public health impact of the vaccine in Kenya, and thus provides early evidence for health administrators and policy makers in Kenya to support the sustained use of the vaccine in the routine national immunization program. However, given the limited period of post-vaccine observation, the changes in RVA strain distribution may not this far be conclusively attributed to the effect of vaccination. Therefore, continued surveillance is necessary to document the long-term impact and effectiveness of rotavirus vaccine on the rotavirus disease burden and strain epidemiology in Kenya.""