baby receiving rotavirus medicine

Maximising the Regional and Global Impact of Rotavirus Vaccination

Rotavirus is a highly infectious stomach bug, and is the most common cause of severe diarrhoea in infants and young children throughout the world. Before the introduction of rotavirus vaccines, over half a million children died from rotavirus diarrhoea each year, and many more were hospitalised. Most deaths occurred in Low and Middle Income Countries (LMICs).

For over 20 years, the University of Liverpool has led a collaborative global programme of research to address this major cause of childhood illness and death. Our work in describing the rotavirus disease burden, epidemiology and the performance of rotavirus vaccines in LMICs has provided crucial underpinning evidence to support the widespread introduction of rotavirus vaccines.

To date, 95 countries have introduced rotavirus vaccine into their infant immunisation schedules, including many countries in Africa. The UK introduced rotavirus vaccination in 2013. The result of the global rollout of rotavirus vaccination has been dramatic. In industrialised nations such as the UK, hospitalisations due to rotavirus diarrhoea are now rare. Child deaths due to rotavirus have fallen to around 200,000 per year, with the impact mainly seen in LMICs.

However, many of the world’s poorest countries have not yet successfully adopted the vaccine and infants continue to suffer preventable diarrhoea and death. Vaccines are only effective if people have access to them, if they work well in their local environment, and if people are willing to use them. Through research in communities from Liverpool, to India, to Malawi, our Institute of Infection and Global Health is helping to improve understanding of the barriers and enablers to deploying rotavirus vaccine at home and around the world.

Cutting infant deaths in Malawi by a third

Liverpool’s Professor Nigel Cunliffe leads a long-term programme of rotavirus research in Malawi, a country with high child mortality due to diarrhoea, with colleagues from the Malawi-Liverpool-Wellcome Trust Clinical Research Programme and the Malawi Ministry of Health. He conducted the first clinical trial of a rotavirus vaccine in Africa, which informed a global vaccine recommendation by the World Health Organisation in 2009 and the subsequent introduction of rotavirus vaccine into Malawi’s childhood immunisation schedule in 2012. Malawi has since developed a strong vaccination programme, rapidly scaling up coverage to over 90% for eligible infants.

The programme has been a resounding success. A study led by Professor Cunliffe and published in 2018, found that children who received the vaccine had a 34% lower risk of dying from diarrhoea. The team visited 1,832 villages in Malawi over four years, collecting data on 48,672 infants, including vaccination status and whether they survived to age one year. This research provided the first population-level evidence from a low-income country that rotavirus vaccination saves lives. These data will help inform vaccination programmes and policies internationally.

Regional responses to global problems

There are geographical differences in the effectiveness of rotavirus vaccination. In particular, the vaccine seems to perform less well in the poorest communities that need them the most. Factors such as high force of infection, maternal immunity, gut bacteria, and prevalence of other infections all affect the body’s response to orally administered vaccines.

Through the RoVi research project led by Professor Miren Iturriza-Gomara, we are investigating in communities in Liverpool, Malawi and India why rotavirus vaccines are less effective in babies in poorer areas. We compare the protection passed from mothers to babies during pregnancy and after birth, and study the bacteria in the baby’s stool from birth to the time of rotavirus vaccination and investigate how gut bacteria may be linked to vaccine response. Dr Khuzwayo Jere, a Wellcome Public Health and Tropical Medicine Training Fellow, is further elucidating the body’s immune response to rotavirus vaccination in Malawi.

Dr Dan Hungerford, a NIHR Postdoctoral Fellow working in collaboration with Public Health England, led a study in Merseyside, UK that demonstrated significant reductions across the healthcare system in the burden of gastrointestinal illness since rotavirus vaccine was introduced. Importantly, despite relatively lower vaccine uptake, the benefit of rotavirus vaccination was found to be greatest among the most deprived populations, where disease burden is highest. Prioritising rotavirus vaccination in the most deprived populations is likely to give the greatest health benefit and can contribute to reducing health inequalities. Ongoing work is examining the barriers and facilitators to vaccination in these communities.

A multi-disciplinary approach

To be maximally successful, vaccination programmes require a multidisciplinary collaborative approach that combines biology, epidemiology, public health, economics, advocacy and outreach, whilst delivering in many culturally diverse environments.

At Liverpool we are playing a leading local and global role. Through surveillance and modelling, we are assessing the current and future impact of rotavirus vaccination programmes in Liverpool and around the world. As leaders of the European Rotavirus Surveillance Network, we are monitoring the distribution of rotavirus strains across Europe, including detecting emerging strains. We continue to evaluate novel rotavirus vaccines in Malawi.

We have already seen a major decrease in illnesses, hospitalisations and deaths from rotavirus around the world, but there is still work to be done. We will continue to be at the forefront of multidisciplinary research to optimise the global use of vaccines and reduce the burden of preventable disease and deaths due to diarrhoea. This includes helping every child receive the best protection against rotavirus regardless of where they are born.

Professor Cunliffe