Publications

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

EDCTP portfolio: Emerging diseases

The PREVAC-UP study is ensuring that additional years’ data are obtained on a range of important experimental Ebola vaccines.

Long-term data on Ebola vaccines

Effective vaccines will be central to the control of future Ebola outbreaks. Following the devastating West Africa Ebola outbreak of 2014–16, Ebola vaccine development has been accelerated globally and several promising vaccines are in the pipeline.

The rVSVΔG-ZEBOV-GP vaccine was initially deployed in the 2018/19 Ebola outbreak in the Democratic Republic of the Congo, and a second vaccine, Ad26.ZEBOV, was introduced later. Nevertheless, there are limited data on their effectiveness.

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The challenge

The global PREVAC consortium has been running a phase IIb trial assessing the anti-Ebola immune responses generated by rVSVΔG-ZEBOV-GP (as a single dose and with a ‘boost’ from the same vaccine) and by Ad26.ZEBOV, with a boost from a second vaccine, MVA-BN-Filo. The trial is taking place in three African countries.

The PREVAC-UP study is enabling the team to extend data collection from one year to five years. A total of 1,400 adults and 1,400 children are being followed to determine the long-term safety of the vaccine regimens and the persistence of protective antibody and cell-mediated immune responses to vaccination.

The project

The PREVAC-UP study will generate long-term data on immune responses generated by two of the most advanced Ebola vaccines, in children as well as adults. It will provide key evidence on the likelihood that individuals remain protected against Ebola infection in the years after vaccination. In particular, the study will provide data on responses in children, who were particularly vulnerable to Ebola in the 2014–16 outbreak and for whom little evidence on vaccine responses currently exists.

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

Effective vaccines will be central to the control of future Ebola outbreaks. Following the devastating West Africa Ebola outbreak of 2014–16, Ebola vaccine development has been accelerated globally and several promising vaccines are in the pipeline.

The rVSVΔG-ZEBOV-GP vaccine was initially deployed in the 2018/19 Ebola outbreak in the Democratic Republic of the Congo, and a second vaccine, Ad26.ZEBOV, was introduced later. Nevertheless, there are limited data on their effectiveness.

.

The global PREVAC consortium has been running a phase IIb trial assessing the anti-Ebola immune responses generated by rVSVΔG-ZEBOV-GP (as a single dose and with a ‘boost’ from the same vaccine) and by Ad26.ZEBOV, with a boost from a second vaccine, MVA-BN-Filo. The trial is taking place in three African countries.

The PREVAC-UP study is enabling the team to extend data collection from one year to five years. A total of 1,400 adults and 1,400 children are being followed to determine the long-term safety of the vaccine regimens and the persistence of protective antibody and cell-mediated immune responses to vaccination.

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 PREVAC-UP study will generate long-term data on immune responses generated by two of the most advanced Ebola vaccines, in children as well as adults. It will provide key evidence on the likelihood that individuals remain protected against Ebola infection in the years after vaccination. In particular, the study will provide data on responses in children, who were particularly vulnerable to Ebola in the 2014–16 outbreak and for whom little evidence on vaccine responses currently exists.

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