Prof Trudi O’Neill, Professor in the
Department of Microbiology and Biochemistry at the University of the Free State (UFS) – whose research over the past 14 years is geared towards the development of a low-cost rotavirus vaccine for use in Africa – recently delivered her inaugural lecture on the Bloemfontein Campus on the topic: Rotavirus: New strategies to outsmart an old foe, a very appropriate topic for the time we live in. Most of her work is funded by the German Research Foundation.
She is a founding member and since 2016 Chairperson of the
African Research Network for Neglected Tropical Diseases (ARNTD). This African-based network aims to empower current and future African researchers to support evidence-based control and elimination of neglected tropical diseases.
Prof O’Neill, known among her colleagues as being passionate about her work, also investigates rotavirus-host interactions and strain diversity in both humans and animals.
She obtained her PhD in Molecular Virology at the University of Pretoria in 2001 and started her career at the Onderstepoort Veterinary Institute. In 2012, she joined the Department of Microbiology and Biochemistry at the UFS.
Burden of the disease
“Rotavirus, a zoonotic infection, competes with adenovirus, cholera, and shigella as the biggest cause (27% of diarrhoea cases) of severe dehydrating diarrhoea in children under five,” says Prof O'Neill.
Repeated infections by rotavirus or other diarrhoea-causing pathogens can cause a number of long-term complications, such as intestinal damage and inflammation, nutrient loss, and malabsorption, resulting in malnutrition and subsequently a weak immune system. Malnutrition at a young age can lead to metabolic diseases such as diabetes in the long run.
She says vaccine effectiveness is dependent on many factors. Those suffering from malnutrition in poor countries with inadequate sanitation and who are living in close contact with animals, are most at risk of severe dehydrating diarrhoea caused by rotavirus infections. Low-income countries saw an efficiency rate of less than 50% compared to middle-income countries' 75% efficiency rate. She says, however, that vaccines have had the biggest public health impact in low-income countries due to the high burden of disease.
Prof O’Neill’s presentation included a review of the research that had been conducted, including diversity studies using genome characterisation (sequencing of more than 100 strains, most of which from Mozambique), lipid studies, and investigations into the use of virus-like particles (VLPs) and subunit proteins as vaccine candidates. Production of VLPs and proteins was explored in insect cells and yeast, exploiting the Biobanks SA Yeast culture collection housed in the Department of Microbiology and Biochemistry. A subunit vaccine containing parts (proteins) of the virus that causes the disease and broad-spectrum antiviral vaccine candidates are some of the strategies she is investigating to combat the long-term effects of rotavirus infections.
Cost and safety
Decades of work in the rotavirus field led to the licensing of the first vaccines to fight the infection in the late 2000s. Prof O’Neill says that there has been a 65% decline in rotavirus-related deaths since 2000, with vaccines being a major contributor to this.
Two of the concerns she pointed out in terms of the vaccine were about safety and cost. For persons with severe immune deficiencies, the vaccine can cause vaccine-derived rotavirus infection.
Addressing the concern about cost,
Gavi, a public–private global health partnership that aims to increase access to immunisation in poor countries, has done great work in providing rotavirus vaccine support to low-income countries.