"Hepatitis A defies logic," says PhD student Jenna Patterson. She is based at the Vaccines for Africa (VACFA), which is affiliated with the Institute of Infectious Disease and Molecular Medicine (IDM). Patterson won the "Best Talk" award for her project: Gathering the evidence on hepatitis A, which she presented at the South African Centre for Epidemiological Modelling and Analysis (SACEMA) Conference, hosted by the Department of Science and Technology and the National Research Foundation.
Patterson explains that in places with little development, people are exposed to the virus at a young age and become immune without ever displaying symptoms. Drinking unfiltered water, using a pit toilet, not washing hands etc. increase the risk of exposure at a young age. Now however, due to socioeconomic developments, we have a mix of people being exposed at a young age while others who live in better conditions are often only exposed when they get older. The problem with this is that infection is more severe in an older person and the virus is still circulating in the population.
Traditionally hepatitis A vaccines are introduced into a population when this population mix starts to happen, and research says that this is the way to go – that it’s the optimal time to do this. Still, cost must be factored in, “The health economics become an important consideration,” says Patterson. The increased rate of late exposure is costing the government in paying for hospitalised cases “and it’s expensive,” she says.
The PhD student is currently working on gathering evidence for the consideration of introducing Hepatitis A vaccines into the South African schedule. She describes her process as non-traditional in the way it uses a mixed-methods approach namely through; systemic reviews, a retrospective folder review, health economic analyses, and mathematical modelling. It’s a broad spectrum.
Patterson describes the approach as: “Including collaboration from different sectors / actors in the vaccine space. And this is also the first time that this methodology is formally being used to consider whether a vaccine could be introduced or not. Not only is the question important, but so is the understanding of how the methods are used in our context.”
Being a mixed-methods project means Patterson needs a way to bring it together. “That way is modelling. My work is supported by SACEMA. My data will be taken together in an epidemiological and economical model to predict what both the health and economic impacts of introducing the vaccine into the public sector could be.”
She highlights that this is the premise from which a recommendation would then be made to the government. Whether it’s viable and cost effective to offer the vaccine in the public sector, bearing in mind that it’s often offered in the private sector. Patterson highlights an important question: “Will it be cost effective for Government to provide this piece of equity?” And is the demand high enough.
For her there are a number of factors that should be weighed when making this decision: “The fatality is low but the cost of hospitalisation is high. You’re in hospital, you’re away from work, you require care from family members. This carries a huge societal burden.”
Speaking to her experience of presenting her work at the SACEMA conference she emphasises the value of getting the opportunity to share in a space with researchers working on similar concepts as an experience that can “help broaden understanding of what’s going on in the field”. She adds, “It also helps you approach your work from different angles. There are a gambit of diseases and a variety of ways those disease are being approached. The importance of hearing others’ feedback on what you’re doing is incredibly valuable.”