Adwoa Bentsi-Enchill on the Revised Global Typhoid Vaccination Policy

Recently, the World Health Organization (WHO) published a revised global typhoid vaccination policy.1 How has it been updated? WHO representative and author of a summary paper addressing this question2, Adwoa Bentsi-Enchill, answered our burning questions about the update.

INFECTIOUS DISEASES CONSULTANT: What’s new in the Revised Global Typhoid Vaccination Policy? Why were these changes made?

 Adwoa Bentsi-Enchill: The revised policy is based on a first-time recommendation by the WHO Strategic Advisory Group of Experts on immunization (SAGE), the principal advisory body to WHO on vaccines and immunization, for typhoid vaccination in children younger than age 2 years using typhoid conjugate vaccines (TCV). TCV is newly licensed for use in infants from age 6 months and in older children and adults up to 45 years old.  While there was a previous global policy on vaccination against both endemic and epidemic typhoid, this was only possible with a parenteral unconjugated Vi polysaccharide vaccine licensed for use in children aged 2 years and above, or an oral live attenuated Ty21a vaccine for persons older than 6 years.

ID CON: What do these changes mean for your global peers in immunization practice?

 ABE: The new policy recommends inclusion of typhoid vaccination in routine childhood immunization programs in typhoid endemic countries. In countries eligible for support from Gavi, the Vaccine Alliance, the policy has facilitated funding opportunities for introduction of TCV into routine use. Typhoid vaccination is also recommended for the control of outbreaks and for at-risk individuals in non-endemic settings when indicated according to the current policy (such as for travelers from non-endemic to endemic areas).

ID CON: Can you talk about the public health burden of typhoid fever and how it has been influenced by recent medical developments?

ABE: I understand the use of “medical developments” to encompass the field of health/medicine in general. My response will focus on the public health context. Typhoid fever burden is estimated at between 11 and 21 million cases and approximately 128,000 to 161,000 deaths annually. The majority of cases occur in South and South-East Asia and sub-Saharan Africa. An additional significant burden is associated with high prevalence and spread of antimicrobial-resistant strains of Salmonella ser Typhi affecting many endemic areas, which leads to increased proportions of patients experiencing clinical treatment failure and complications, an increased likelihood of hospitalization and prolonged admission, and the need to use more expensive treatment options that are least affordable for the populations with the most need for typhoid treatment.

The pattern of antimicrobial resistance, particularly the emergence of an extensively drug-resistant (XDR) strain of S Typhi that caused an outbreak in the Sindh Province of Pakistan starting in 2017, has given rise to grave concerns about dangerously narrowing options for effective clinical management of typhoid fever.

Recent and ongoing epidemiological studies as well as genomic studies are making significant contributions to the understanding of the public health burden of typhoid and its transmission, and will inform control strategies. With its suitability for use at a younger age, improved immunological properties and longer duration of protection, TCV is expected to have a significant impact on the burden of typhoid fever. However, this is yet to be fully demonstrated.

ID CON: What about treatment-resistant strains of S Typhi? How did the policy writing panel incorporate them into the new Vaccination Policy?

ABE: In developing the new vaccination policy, SAGE and WHO took note of the disease and economic burden associated with antimicrobial resistant strains (as described previously), which helped make the case for routine vaccination as a control strategy against typhoid.  The potential impact of vaccination to reduce antimicrobial resistance associated with typhoid, through decreased transmission of S Typhi or reduction in inappropriate use of antibiotics, was considered. However, such impact is yet to be fully assessed.

ID CON: Which medical advancements are you (and/or the policy writing panel) hoping for in the coming years?

ABE: From a public health perspective, key advancements that are expected to have a meaningful impact in helping reduce the public health burden of typhoid fever include:

  • Sustainable investments for improved access by at-risk populations to safe water;
  • Sanitation and hygiene (WASH) services;
  • A ready-to-use, rapid, and affordable diagnostic with improved sensitivity to enhance clinical diagnosis of cases to guide appropriate antibiotic use and to strengthen surveillance of typhoid; and
  • Accelerated research and development of new antibiotics to treat resistant typhoid.

An integrated approach that combines vaccination with other control strategies such as WASH, health education, and training of health professionals in appropriate diagnosis and treatment of cases is needed and would go a long way toward achieving the long-term goal of typhoid control and possibly elimination.


  1. Typhoid vaccines: WHO position paper–March 2018. World Health Organization. Wkly Epidemiol Rec. 2018;13(93):153-172.
  2. Bentsi-Enchill AD, Hombach J. Revised global typhoid vaccination policy. Clin Infect Dis. 2019; 68(Suppl. 1):S31-S33.