Tackling typhoid fever in sub-Saharan Africa

Latest estimates indicate that there are around 9 million cases of typhoid fever annually worldwide, resulting in around 110,000 deaths per year. An overwhelming majority of these cases occur in sub-Saharan Africa in nations with inadequate sanitation and poor access to clean water.

Typhoid fever is a life-threatening bacterial infection caused by Salmonella typhi bacteria, usually spread through contaminated food or water. Once Salmonella Typhi bacteria are ingested, they multiply and spread into the bloodstream.

Symptoms typically include sustained fever, headache, abdominal pain, and diarrhoea. In severe cases, complications such as intestinal perforation or bloodstream infection can occur, which can be life-threatening if not treated promptly with antibiotics.

Whilst typhoid fever is treatable, the effects can go beyond illness and death. It can impair physical and cognitive development in children, affect school attendance and performance, limit productivity, and reduce earning potential.

Sadly, school age and pre-school children who have not yet developed a strong enough immune system to fight the bacteria are at most risk of typhoid. The emergence of multi-drug resistant strains of Salmonella Typhi bacteria is adding more complexity to what is already a significant burden in the world’s poorest nations. Therefore, the only real solution to put control back in the hands of healthcare workers in a timely way is through a vaccine programme.

The Typhoid conjugate vaccine (TCV) is the first major advance in typhoid vaccines in a generation and the the only typhoid vaccine licenced for children as young as 6 months. A single dose of TCV is a safe and cost-effective way to prevent typhoid fever and save lives in Malawi

Professor Melita Gordon led a clinical trial in Blantyre, Malawi that showed that the TCV is safe and 84 percent effective in protecting against typhoid. This study lasted from 2018-2022 and was part of the Typhoid Vaccine Acceleration Consortium (TyVAC) study, funded by the Bill & Melinda Gates Foundation.

This efficacy data was a critical first step leading to a national roll out in Malawi, which started with a mass campaign for all children aged 9 months through to 15 years.

Professor Melita Gordon and Golden Kondowe, the first child in Malawi to receive the Typhoid conjugate vaccine.

This clinical trial was the culmination of 20 years of research focused on salmonella disease in Malawi and following from its success, more than 7 million children in Malawi have received TCV, in one of the largest immunisation campaigns ever conducted in the country. The vaccine is now being included as routine for all children going forward.

The most recent study published in The Lancet has shown that a single dose of TCV is over 78% percent effective in protecting children in Malawi across at least 4 years.

These are the longest-term data on Typhoid Conjugate protection yet published globally, and are part of the Typhoid Vaccine Acceleration Consortium (TyVAC), which aims to accelerate introduction of TCV as part of an integrated approach to reduce the burden of typhoid in countries eligible for support from Gavi, the Vaccine Alliance. The findings are critical as typhoid is an increasing public health threat across sub-Saharan Africa due to the emergence and spread of multi-drug resistant strains and extreme weather events occurring in Malawi.

The groundbreaking research being conducted at MLW promises to save lives, strengthen resilience and improve economies throughout Africa.

A child from Malawi recieving the Typhoid conjugate vaccine.

Professor Melita Gordon moved to Malawi 25 years ago to join the Malawi-Liverpool-Wellcome-Trust and dedicate her career to the field of enteric diseases research and find equitable solutions for the people of Malawi and across Africa.