This cluster randomised trial will examine the impact of introducing TyphiBEV, a typhoid conjugate vaccine licensed in India, on the incidence of typhoid fever in a high burden urban setting in South India.
TyphiBEV®, a typhoid conjugate vaccine from Biological E, has been licensed by the Central Drugs Standard Control Organaisation in India based on immunogenicity and safety data. A similar typhoid conjugate vaccine has been demonstrated in large clinical trials to provide 80% vaccine efficacy in Nepal and Bangladesh. The TyphiBEV® has not been similarly evaluated. The demonstration of the impact of a city-scale typhoid conjugate vaccine introduction on the burden of typhoid will aid policy decisions on the use of typhoid conjugate vaccines in the national immunisation program. After written informed consent, the investigators will establish stimulated passive surveillance in 72,000 individuals between 1 and 30 years of age within the Vellore Demographic Surveillance System to determine the incidence of blood-culture confirmed typhoid fever. Thirty-six thousand surveillance participants between 1 year and 30 years residing in the 30 clusters (areas) randomised to receive the vaccine will receive the vaccine at the beginning of the trial. Those in other areas will receive the same at the end of two years. Using a stimulated passive surveillance approach, those with acute febrile illness will be encouraged to visit study surveillance hospitals. Participants will be evaluated for blood-culture confirmed typhoid fever if they are eligible. The incidence of typhoid among those living in areas assigned to vaccination compared to those whose residence is in areas not designated for vaccination will be used to calculate the impact of the vaccine on disease burden.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
72,500
TyphiBEV is a clear colourless monovalent vaccine containing 25 µg of Typhoid Vi polysaccharide manufactured using the Citrobacter freundii sensu lato3056 (Vi) and is conjugated to CRM 197 as a carrier protein. Sodium chloride and Phosphate buffer are used as a buffering agent in the vaccine formulation with 2-Phenoxyethanol as a preservative.
Christian Medical College Vellore
Vellore, Tamil Nadu, India
RECRUITINGTotal effect
Number of blood culture confirmed typhoid fever episodes in vaccinated participants from vaccine clusters compared to the number of blood culture confirmed typhoid fever episodes in unvaccinated participants from non-vaccine clusters
Time frame: at 24 months of follow up beginning 28 days after vaccine introduction in vaccine clusters.
Overall effect
The number of blood culture confirmed typhoid fever episodes in participants from vaccine clusters compared to the number of blood culture confirmed typhoid fever episodes in participants from non-vaccine clusters
Time frame: at 24 months of follow up beginning 28 days after vaccine introduction in vaccine clusters.
Effect in children 1 to 14 years
The number of blood culture confirmed typhoid fever episodes in vaccinated children between 1 year and 14 years and 364 days from vaccine clusters compared to the number of blood culture confirmed typhoid fever episodes in unvaccinated children between 1 year and 14 years and 364 days from non-vaccine clusters
Time frame: at 24 months of follow up beginning 28 days after vaccine introduction in vaccine clusters.
Effect on all febrile illness requiring healthcare visits
The number of febrile illness episodes where healthcare is sought among vaccinated participants from vaccine clusters compared to unvaccinated participants from non-vaccine clusters
Time frame: at 24 months of follow up beginning 28 days after vaccine introduction in vaccine clusters.
Safety outcomes
The number and description of solicited and non-solicited adverse events reported within the first seven days after vaccination in the safety subset of vaccine recipients
Time frame: Seven days after vaccine receipt
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.