Typhoid affects 14 million people each year, with the highest rates in children, and causes around 150,000 deaths.
In order to accelerate vaccine introduction, the team led by Professor Andrew Pollard developed a model of human infection in Oxford in which volunteers drank a suspension of typhoid bacteria to deliberately get typhoid infection, so that they could test new vaccines. They studied the model carefully and made some important new observations about how the bacteria cause disease identified potential new approaches to diagnosis.
They tested a new generation typhoid vaccine using the Oxford model and showed that it worked. The data from this study supported World Health Organisation (WHO) global policy recommendations on use of the vaccine for all children from 9 months to 15 years of age in high burden areas, and release of $85M funding by the Global Alliance for Vaccines and Immunisation (Gavi) to help low income countries introduce the vaccine.
Data on disease burden is important for countries to decide whether to prioritise vaccine introduction. The team led studies in Nepal, Bangladesh and Malawi to provide burden data in field studies of 100,000 people in each country. These data were also considered by WHO in their deliberations on global policy and provided a base for large field trials which they have undertaken to evaluate implementation of typhoid vaccine funded by the Bill & Melinda Gates Foundation. In these trials they have vaccinated over 100,000 children against typhoid and found that the vaccine prevented 82% of infections. They also showed that the vaccine was safe, data used by WHO in their policy position paper on typhoid vaccine safety.
Vaccine roll out has begun and 10 million doses were deployed at the end of 2019 to control an outbreak of typhoid resistant to most antibiotics in Pakistan. Many countries are now planning introduction of the vaccine as global roll out begins, with the next deployments being in Zimbabwe and Liberia.
Funded by the Bill and Melinda Gates Foundation