Publications

Funding for clinical research |drugs, vaccines, microbicides, diagnostics | HIV/AIDS, tuberculosis, malaria, other infectious diseases |sub-Saharan Africa

Dr Boris Kevin Tchounga

Côte d'Ivoire

EDCTP portfolio: Career Development Fellowships

Dr Boris Kevin Tchounga aims to establish epidemiological data for HIV-2, improve the diagnosis of HIV-2 patients and better understand HIV-2 disease progression, with a view to improving the holistic care of people living with HIV-2.

Immunological markers of HIV-2 infection

Human immunodeficiency virus type 2 (HIV-2) is a retrovirus responsible for an AIDS epidemic localised in West Africa, were the circulation of both HIV-1 and HIV-2 leads to co-infections with both viruses. The HIV-2 infection is characterised by a longer asymptomatic phase and a slower disease progression than HIV-1 infection, as well as the intrinsic resistance of HIV-2 to non-nucleoside reverse transcriptase inhibitors. It is mandatory to differentiate HIV-1 from HIV-2 infection before initiating antiretroviral therapy (ART), but the diagnosis is still challenging, especially for the HIV-1 and HIV-2 dually infected individuals

The challenge is to explore new diagnostic algorithms based on routinely used HIV rapid tests, to ensure the peripheral diagnosis of patients with dual infection in West Africa. The related challenge is to describe the epidemiology of HIV-2 and dual infection in West Africa.

The challenge

Guidelines for antiretroviral therapy neglect HIV-2 infected patients due to conflicting reports on the epidemic trend of HIV-2 infection and a lack of recent data. Furthermore, the important mortality reported among HIV-2 infected individuals may be the consequence of immune activation and persistence of soluble biomarkers as demonstrated in HIV-1 infection.

Dr Tchounga’s three-year research project relies on the West African HIV-2 cohort, and the related biobank to evaluate a new diagnostic algorithm for HIV-1 and HIV-2 dual infection. The study will also produce more accurate and updated epidemiological data on HIV-2 infection. Finally, it is exploring disease progression and the prognostic role of immunologic and inflammatory markers in HIV-2 infection.

The project

The project aims to provide the much needed accurate epidemiologic data, improved diagnosis of HIV-2 patients and a better understanding of the dynamics and correlates of disease progression. These results may help inform specific guidelines for HIV-2 infection. Capacity development is integrated into the project through training of graduate students in epidemiology, immunology and biostatistics.

Impact


test the safety and efficacy of this new formulation in young children

Bringing antiretroviral drugs to children

The CHAPAS trials have ensured that many more children with HIV have benefited
from life-saving antiretrovirals.

EDCTP portfolio: HIV & HIV-associated infections

The challenge

Human immunodeficiency virus type 2 (HIV-2) is a retrovirus responsible for an AIDS epidemic localised in West Africa, were the circulation of both HIV-1 and HIV-2 leads to co-infections with both viruses. The HIV-2 infection is characterised by a longer asymptomatic phase and a slower disease progression than HIV-1 infection, as well as the intrinsic resistance of HIV-2 to non-nucleoside reverse transcriptase inhibitors. It is mandatory to differentiate HIV-1 from HIV-2 infection before initiating antiretroviral therapy (ART), but the diagnosis is still challenging, especially for the HIV-1 and HIV-2 dually infected individuals

The challenge is to explore new diagnostic algorithms based on routinely used HIV rapid tests, to ensure the peripheral diagnosis of patients with dual infection in West Africa. The related challenge is to describe the epidemiology of HIV-2 and dual infection in West Africa.

Guidelines for antiretroviral therapy neglect HIV-2 infected patients due to conflicting reports on the epidemic trend of HIV-2 infection and a lack of recent data. Furthermore, the important mortality reported among HIV-2 infected individuals may be the consequence of immune activation and persistence of soluble biomarkers as demonstrated in HIV-1 infection.

Dr Tchounga’s three-year research project relies on the West African HIV-2 cohort, and the related biobank to evaluate a new diagnostic algorithm for HIV-1 and HIV-2 dual infection. The study will also produce more accurate and updated epidemiological data on HIV-2 infection. Finally, it is exploring disease progression and the prognostic role of immunologic and inflammatory markers in HIV-2 infection.

The project

The later CHAPAS-3 trial compared the efficacy and safety of three fixed-dose combinations including two without stavudine (found to have some long-term side effects in adults, leading to a recommendation that its use be discontinued in children). The trial the first of its kind in Africa studied nearly 500 children at four sites in two African countries.

The project aims to provide the much needed accurate epidemiologic data, improved diagnosis of HIV-2 patients and a better understanding of the dynamics and correlates of disease progression. These results may help inform specific guidelines for HIV-2 infection. Capacity development is integrated into the project through training of graduate students in epidemiology, immunology and biostatistics.

ratios forfixed-dose combinations and on appropriatedosage according to weight. 

The CHAPAS-3 trial confirmed the effectiveness of fixed-dose combinations, providing further impetus to the rollout of antiretrovirals to children. Its evidence on abacavir informed the WHO recommendation of abacavir-containing combinations for first-line therapy in children. Trial data have also been used to support applications for regulatory approval for new scored efavirenz tablets.

Impact

L’homme RF et al. Nevirapine, stavudine and lamivudine pharmacokinetics in African children on paediatric fixed-dose combination tablets. AIDS. 2008;22(5):557–65.

Mulenga V et al. Abacavir, zidovudine, or stavudine as paediatric tablets for African HIVinfected children (CHAPAS-3): an open-label, parallel-group, randomised controlled trial. Lancet Infect Dis. 2016;16(2):169–79.

WHO. Guidelines on the use of antiretroviral drugs for treating and preventing HIV infection: recommendations for a public health approach. 2010.

WHO. Consolidated guidelines on the use of antiretroviral drugs
for treating and preventing

HIV infection: Recommendations for a public health approach
(second edition). 2016

Projects: Children with HIV in Africa Pharmacokinetics and Adherence of Simple Antiretroviral Regimens (CHAPAS): CHAPAS-1 and -3

Project lead: Professor Chifumbe Chintu, University Teaching Hospital, Zambia (CHAPAS-1); Dr Veronica Mulenga, University Teaching Hospital, Zambia (CHAPAS-3)

Target population(s): Children with HIV

Sample size: 71 (CHAPAS-1); 480 (CHAPAS-3)

Countries involved: Ireland, the Netherlands, the UK, the USA, Zambia (CHAPAS-1); Uganda, Zambia (CHAPAS-3)

Project duration: 2005–2009 (CHAPAS-1); 2010 –2011 (CHAPAS-3)

EDCTP funding: €1.2M (CHAPAS-1); €4.6M (CHAPAS-3)

Total project funding: €1.2M (CHAPAS-1); €5.0M