Goal of the unit is to provide a platform for coordinated development and deployment of state-of-the-art technologies and analyses, which can be utilized effectively for vaccine discovery, and early development and testing of clinical products.
The unit has added to its portfolio three of the top five aetiological agents of childhood diarrhoea namely (i.e. Enterotoxigenic E coli (ETEC), Shigella and Salmonella) from the two (Rotavirus and Vibrio Cholerae) it had been working on in the past.
The studies that have started this year
- Increasing the efficacy and effectiveness of licensed vaccines:
- A randomized controlled trial of two versus three doses of Rotarix vaccine for boosting and longevity of vaccine immune responses in Zambia (ROVAS-2). This study aims at trying to adapt the current dosing regimen of the Rotarix given at 6 and 10 weeks to a three-dose regimen with an added dose at 9 months of age. We will evaluate the both the magnitude and longevity of immunogenicity in the second year of life.
- A randomised controlled trial comparing to vaccination regimen of oral cholera vaccine, the standard two dose given 14 days apart and the experimental two doses but given at 6 months following the first dose of the vaccine. We will be evaluating age-specific serum vibriocidal titers in participants to determine if the delayed dosing regimen is comparable to the standard regimen. The implication will be having an alternative
dosing schedule which can be deployed in outbreak situations and humanitarian crises.
2. Determining safety, reactogenicity, immunogenicity and efficacy of new vaccines:
- A phase IIb An Open-label, Randomized, Controlled, Single Centre, Phase IIb Study to Assess the Immunogenicity, Reactogenicity and Safety of Three Live Oral Rotavirus Vaccines, ROTAVAC®, ROTAVAC 5CM and Rotarix® in Healthy Zambian Infants. This is the first trial to be done in Africans to determine if this vaccine could be an option to the current licensed Rotarix™ used in the national immunisation program.
- A Phase 1 age descending placebo controlled clinical trial to examine the safety, tolerability, and immunogenicity of an oral inactivated ETEC Vaccine (ETVAX®) with dmLT adjuvant in healthy adults and children in Zambia. This study is the first one that will utilise data from endemic countries as basis for its licensure unlike other vaccines that were first tested and licensed using data from developed countries.
- A Phase 3 double-blind, randomized, active comparator-controlled, group-sequential, multinational trial to assess the safety and efficacy of a trivalent P2-VP8 subunit rotavirus vaccine in prevention of severe rotavirus gastroenteritis in healthy infants. This study will test a new candidate vaccine for use in neonates which is an injectable vaccine aimed at circumventing the challenges low efficacy and immunogenicity in developing countries faced by oral rotavirus vaccines
3. Developing a model of evaluating new vaccines that is aimed at accelerating vaccine development. The unit is currently a recipient of two pump priming grants from the HICVAC network to set up a model for evaluating new rotavirus vaccines and another one for evaluating new typhoid vaccines. These models are collectively called Human Infection Challenge Models and have advantages of requiring few subjects and shorter periods of time to evaluate candidate vaccines. The unit is currently developing both clinical and laboratory capacity to be able to set these models in preparation for actual testing of candidate vaccines.
4. Additional laboratory capacity
- Evaluating and validating a rapid diagnostic assay for ETEC and shigella. We are validating an assay that can be used in resource limited setting and has a ~60minute turn around time from sample collection to results. We hope that if this will strengthen the current surveillance system for the two pathogens and help with management of diarrhoea associated with these pathogens.
The unit has also added to its vaccine evaluating assays the Vibriocidal assay. This assay will help determine and quantify the functional immune responses to oral cholera vaccine in the both local and regional studies because our laboratory is the only one in the region to have this capacity. This assay has been established with the help of Mr. John Mwaba one of our unit PhD student that trained at JHU.