Many typhoid-endemic countries are prone to extreme weather events. Heavy rainfall, cyclones, and typhoons can lead to floods, which may damage water, sanitation, and hygiene (WASH) infrastructure. Floods can overwhelm water systems, resulting in drinking water contaminated with bacteria. Drought conditions can force communities to use shallow water sources that are more likely to be contaminated with bacteria, including typhoid. These extreme weather events affect access to and use of safe water, increasing the risk of typhoid.
Typhoid conjugate vaccines (TCVs) provide protection against typhoid and serve as a defense against the heightened risk of disease associated with adverse weather events.
Typhoid protection when climate disasters hit
In the past several years we have seen many typhoid-endemic countries affected by severe climate disasters—from floods in Kenya, Pakistan, and Bangladesh, to droughts in Zimbabwe, cyclones in Malawi, and heatwaves in Burkina Faso. These weather extremes complicate typhoid prevention and control programs in many countries in Africa and Asia.
A health care worker administers TCV during a 2022 campaign in Pakistan. Credit: TyVAC/PHC Global
In July 2022, catastrophic floods severely overwhelmed Pakistan’s WASH infrastructure, contaminating water supplies, displacing millions of people, and escalating the risk of typhoid in the midst of a TCV campaign. Already grappling with extensively drug-resistant (XDR) typhoid, the widespread damage from the floods raised the urgency for typhoid prevention measures. In spite of these challenges, Pakistan successfully completed the final phase of its nationwide TCV rollout. Pakistan has now integrated TCV as part of its routine immunization program, offering a vital tool to prevent typhoid disease and transmission.
In Malawi, Cyclone Freddy caused widespread devastation a few days before a long-planned TCV introduction campaign in 2023. The cyclone destroyed communities and overwhelmed sewage systems, contaminating clean water supplies. The unexpected extreme weather raised concerns about potential typhoid outbreaks preceding the planned TCV introduction. The Government of Malawi and partners ultimately moved forward with the TCV campaign, recognizing the urgency to protect children against typhoid, particularly in the wake of a damaging cyclone. Children can now receive TCV during their 9-month well child visit.
Children collect their vaccine cards after receiving TCV during a campaign in Burkina Faso. Credit: TyVAC/Build Africa Communications
In Bangladesh, the delta plains and tributaries of rivers occupy nearly 80% of the country. Millions of people live in lowland communities and confront the triple challenge of substantial typhoid burden, inadequate WASH infrastructure, and frequent flooding. The country has one of the highest typhoid burdens in the world and experiences frequent flash floods that severely damage WASH infrastructure, contaminating limited safe water sources. Bangladesh plans to introduce TCV to protect children from typhoid and reduce the potential for typhoid outbreaks.
Prolonged dry seasons have led to droughts across parts of Southern Africa, leading to significant water shortages. Zimbabwe faced recurring typhoid outbreaks prior to TCV introduction in 2021. The emergence of drug-resistant typhoid further complicated treatment efforts, highlighting the need for effective prevention measures. Children in Zimbabwe now receive TCV at their 9-month routine visit, ensuring they are protected from typhoid when climate-related events occur.
TCVs act as a guard
TCVs act as a protective guard, providing crucial defense against typhoid. The frequency of extreme weather events is increasing; it is urgent to vaccinate children against typhoid to provide protection ahead of these extremes. When more children are vaccinated against typhoid, transmission decreases and communities stay healthier and more resilient in the midst of severe weather events.
Cover photo: A child receives TCV during Malawi’s introduction campaign in 2023. Credit: TyVAC/Madalitso Mvula
