AKU played a crucial role in addressing an outbreak of extensively drug-resistant typhoid in Sindh, and contributed to Pakistan’s decision to become the first country in the world to use a new typhoid vaccine on a routine basis.
Now the University is conducting the world’s first evaluation of the impact of the typhoid conjugate vaccine in a routine immunisation programme.
Caused by the bacterium Salmonella Typhi and characterised by symptoms including fever and diarrhoea, typhoid afflicts 14 million people and kills roughly 220,000 every year, typically in poor communities in Asia and Africa that lack access to safe drinking water.
As the bacterium evolves to become extensively drug-resistant, it becomes an even greater threat because the risk of complications increases and treatment grows more difficult and expensive. Improved water and sanitation facilities play a key role in preventing new cases of typhoid, but they represent an expensive, long-term fix. In the short-term, the only solution is a vaccine, which prevents people from catching typhoid in the first place.
“The vaccine represents the most cost-effective and rapid approach to preventing new cases of typhoid,” said Associate Professor Farah Naz Qamar, principal investigator of the study, which is being funded by Gavi, an alliance of international organisations that works to increase vaccination rates, especially in poor countries.
To determine whether the vaccine has had an impact on antibiotic resistance and has helped decrease the number of typhoid cases, the study will analyse data on cases from hospitals across Sindh and Punjab over the three years prior to the vaccine’s introduction, comparing it to data on cases that have emerged up to three years after the launch of the immunisation campaign.
Researchers are also following a group of children who have received the vaccine to assess the duration of their immune response following administration of a single dose of the typhoid conjugate vaccine.
The study is expected to inform decisions on whether booster shots are needed to provide better and longer-lasting protection against the disease. The evaluation of the impact of the vaccine will provide crucial information for policymakers in other typhoid-endemic countries like Bangladesh and Nepal, which are considering introducing the vaccine.
Dr Qamar’s co-investigators at AKU are Assistant Professor Sonia Qureshi, Assistant Professor Momin Kazi, Associate Professor Seema Irfan, Senior Instructor Tahir Yousafzai and Professor Asad Ali.