Rational drug and vaccine design refer to developing next-generation drugs and vaccines based on knowledge of the biological target or infectious agent. At the Department of Microbiology & Biochemistry, drug and vaccine development focuses on infections and diseases affecting humans, animals and plants.
HUMAN VACCINE DEVELOPMENT
- Rotavirus causes severe, dehydrating diarrhoea, which can be fatal, especially in resource-poor settings.
- Next-generation rotavirus vaccines are being developed to improve child health in the Sub-Saharan African region.
- Non-replicating vaccines cannot replicate in the host. Research is focused on virus-like particle production in yeast and the expression of immunogenic proteins in yeast and bacteria.
- Reassortant rotaviruses can be engineered using reverse genetics. Such engineered viruses can be used as vaccine candidates that match circulating field strains for improved protection.
DRUG DEVELOPMENT/DISCOVERY
- Structure-guided drug design uses the three-dimensional structures of proteins for drug discovery. Efforts are in progress to design drugs against novel targets in opportunistic pathogenic fungi using X-ray crystallography.
- We study drugs already approved to treat one disease or condition and see if they are safe and effective for treating other conditions. In particular, drugs are repurposed to control the growth of some fungal pathogens. This practice is favourable in developing countries due to known toxicology risks.
- Hormones play essential regulatory and signalling roles. Equine chorionic gonadotropin has unique properties when administered to non-equids widely used in animal breeding for improved reproductive success. Purification and recombinant production of this hormone are the current focus.
- Phage therapy involves the treatment of pathogenic bacterial infections with bacteriophages and viruses that specifically replicate in bacteria. Phage treatment of Escherichia coli infection in poultry and calves is currently under investigation at the UFS as an alternative treatment option to antibiotics.
VETERINARY DRUGS AND VACCINES
- The control of important diseases in animals remains the top research priority of the group.
- Disease control options can include vaccine development, where infectious coryza, caused by Avibacterium paragallinarum, remains the flagship project in terms of vaccine development and improved diagnostics.
- Various expression-based projects are currently underway. The spike protein of infectious bronchitis virus (an avian coronavirus) has been successfully expressed in our yeast-based expression system, opening the way for possible SARS-CoV-2 expression. Efforts are being made to express antiviral peptides discovered through phage display technology.
- The expression of various enzymes for limiting mycotoxin problems in poultry and improving feed conversion ratios are also under investigation.
Prof Robert Bragg
Vaccine development for animals,
virology and bacteriophages
BraggRR@ufs.ac.za