Typhoid is a serious and life-threatening enteric fever that remains a substantial public health issue for children and adolescents. Owing to the advancements in hygiene and sanitation infrastructure, typhoid fever has been largely eliminated in high-income countries. However, the burden of disease remains high in low-and middle-income countries.
The TCV has the potential to be the game-changer in typhoid elimination efforts. The WHO recommends TCV for use in typhoid-endemic countries or those with high levels of antimicrobial-resistant S. Typhi. TCV is preferred for all ages due to its improved immunological properties, suitability for young children, and potential for sustained immune protection, and should be included in routine immunizations for children in high-burden settings.
In her doctoral dissertation, Rabab Batool assessed the effectiveness of TCV among the high-risk population of children 6 months to 15 years old. She further assessed the acceptance of this new vaccine among parents. She also assessed the efficacy and safety of several typhoid vaccines in typhoid-endemic settings to compare the performance of the new vaccine.
Based on Batool’s findings, the TCV is the most effective of all previously licensed vaccines and is safe for children under 2 years old. The vaccine protected the children against culture confirmed S. Typhi infection in typhoid outbreak setting. Lack of parental awareness regarding new vaccine introduction and negative perceptions and attitudes towards vaccines were barriers to TCV vaccination uptake among children.
Research evidence aligns with WHO recommendations
The current recommendation by WHO is a single dose of TCV for infants and children from 6 months of age. Batool confirmed the performance of a single shot of TCV in the real-life field setting with a high burden of antimicrobial resistant S. Typhi. The findings of Batool’s research align with the WHO recommendations.
The results reveal lower efficacy among children under 5 years old compared to older children. Most children in endemic countries will receive the shot at the age of 9 months. Based on her thesis results, Batool recommends considering a booster dose for children vaccinated before age 2, around the time they start school, to maintain TCV protection during the school years when they are most at risk of typhoid.
To effectively achieve the goal of typhoid elimination, vaccination efforts must be complemented with ongoing initiatives aimed at improving water and sanitation practices, ensuring accurate diagnosis and treatment of typhoid fever, and identifying and treating asymptomatic carriers. Also, it is critical to tackle the rising trend of antimicrobial resistance in low- and middle-income countries.
“The evidence from my research supports the use of TCV as a promising tool in the fight against typhoid fever, preventing the spread of extensively drug-resistant S. Typhi strains, and ultimately saving lives,” Batool says.
Batool is from Pakistan. She is a doctoral student at Tampere University and working as a Research Manager at Dopasi Foundation, Pakistan.
Public defence on Friday 25 April
The doctoral dissertation of M.Sc. Rabab Batool in the field of paediatrics titled Impact assessment of typhoid conjugate vaccine in the South Asian slums will be publicly examined at the Faculty of Medicine and Health Technology at Tampere University at 12.00 on Friday 25 April 2025. The venue is Kauppi campus, Arvo building, auditorium F114 (Arvo Ylpön katu 34, Tampere). The Opponent will be Professor Heikki Peltola from the University of Helsinki. The Custos will be Professor Per Ashorn from Tampere University.