On World Hepatitis Day, Clinical Associate Professor, Dr Shevanthi Nayagam, working across the School of Public Health and Department of Metabolism, Digestion, and Reproduction, shares how her research is helping shape global and national strategies to eliminate hepatitis B (HBV). From modelling vaccine impact to supporting birth dose policies in Africa, she highlights the power of evidence, collaboration, and local action in tackling this silent epidemic.
Hepatitis B is a virus that attacks the liver and, over time, can cause serious complications such as cirrhosis and liver cancer. What makes it particularly dangerous is that many people don’t realise that they are infected – it can silently damage the liver for years without causing symptoms.
One of the things that motivated me to start research in hepatitis B over a decade ago, was just how little attention this virus received, despite affecting 254 million people. In 2022 it was estimated to have caused 1.1 million deaths. I’ve seen how hepatitis B continues to affect the lives of those living with the infection and their families – particularly in low- and middle-income countries where prevention, diagnosis and treatment are often out of reach.
My translational research sits at the intersection of clinical epidemiology, modelling, and health economics – all aimed at an overarching goal: supporting countries to eliminate viral hepatitis through evidence-based decision making.
A big part of my work involves connecting the global with the local. This dual approach helps ensure that international recommendations are grounded in real-world data . Of course, this kind of work isn’t done in isolation. Everything we do depends on strong collaboration with a wide range of partners – including clinicians, scientists, ministries of health, policy makers and funding agencies.
In 2016, our team’s research helped inform the initial World Health Organization (WHO) targets for hepatitis B elimination. We created a mathematical model to understand what levels of vaccination and treatment would be needed to make elimination of HBV ‘as a public health threat’ possible. Since then, we have contributed to other WHO clinical guidelines and have supported national governments in developing hepatitis strategies that are tailored to local needs. This has included projects in China, South Africa, and Senegal. Our hepatitis B model is also part of the Vaccine Impact Modelling Consortium – which helps estimate the public health impact of a portfolio of vaccines – and has supported global funding and policy decisions.
One key area of focus now is stopping the virus at the very start of life. In high-burden regions, the main way hepatitis B is spread is from mother to child at birth. To prevent this, WHO recommends a first dose of hepatitis B vaccine – known as the “birth dose” – within 24 hours of birth. One of our modelling studies suggests that if coverage of this early dose were scaled up to the WHO target of 90%, more than half a million deaths could be prevented in the African region, alone.
Despite its potential and low cost, fewer than 1 in 5 babies in the African region receive the birth dose on time. This is due to a myriad of multi-faceted challenges, but one contributing factor is the lack of local evidence. Most of what we know about how well the birth dose works comes from Asia – where epidemiology and health systems can differ from African settings. To help fill this knowledge gap, we’re running a multi-country study in Ethiopia, The Gambia, and Senegal. The goal is to understand how effective the birth dose is at preventing mother-to-child transmission of hepatitis B in African contexts. We hope this research will provide crucial extra evidence for ministries of health to adopt or expand birth dose vaccination policies – which would help protect many babies from a lifelong infection. This work is especially timely, as Gavi – the largest funder of vaccines in LMICs – has recently launched a programme to support countries to introduce the birth dose vaccine.