Combined Vi Vaccination and Health Education Program on the Burden of Typhoid in Childhood
Condition: Typhoid; Paratyphoid Fever
MeSH terms: Typhoid Fever; Paratyphoid Fever
Study type: Interventional
Phase: Phase 4

Summary: 
      This study is part of the International Vaccine Institute's (IVI's) typhoid Vi demonstration
      project that aims to accelerate the rational introduction of Vi vaccines in typhoid endemic
      countries. The purpose of this study is to determine the effectiveness of the Vi vaccine
      following a mass typhoid immunization campaign in an endemic area in Karachi, Pakistan. The
      cost-effectiveness of Vi vaccination and the logistic feasibility of a mass typhoid
      immunization campaign will also be evaluated.
    

Detailed description: 
      Typhoid fever is a major cause of morbidity worldwide. The disease predominantly affects
      school-aged children, is more prevalent in urban areas, may last for several weeks and can
      lead to serious complications. Management of this disease is further complicated by the
      emergence of multi-drug resistant strains. Vaccination of high risk populations is considered
      the most promising strategy for the control of typhoid fever. The Vi polysaccharide vaccine
      has been targeted for accelerated introduction into public health programs due to the
      following reasons: it has been shown to have consistent efficacy results even in areas of
      high typhoid incidence; is given as a single dose; lacks patent protection and requires less
      strict cold chain requirements. A cluster-randomized trial involving the Vi polysaccharide
      vaccine and an active control (hepatitis A) was designed to determine the effectiveness and
      the feasibility of providing Vi vaccine under actual programmatic conditions in 3 urban slums
      in Pakistan. The vaccines used in this study are internationally produced and locally
      licensed. A complimentary, targeted, basic typhoid prevention health education program for
      the entire population at the initiation of the project will be provided and the actual
      Vi-demonstration project will be preceded by a 12-month typhoid surveillance activity.

      Secondary objectives of this trial are:

        -  To monitor the adverse events following a routine Vi mass vaccination campaign;

        -  To assess the knowledge, attitudes, beliefs and practices among parents and health care
           providers regarding typhoid illness, treatment and prevention; and

        -  To study typhoid fever risk factors in the population.

      A nested, prospective matched case-control study is included in the trial in order to study
      typhoid risk factors among children in Karachi.
    

Intervention name(s): Typhoid Vi vaccine; Hepatitis A vaccine
Intervention type(s): Biological; Biological
Intervention description(s): Single 0.5ml dose containing 25ug purified Vi polysaccharide of S. typhi.; single 0.5ml dose contains 720 EL.U. of inactivated hepatitis A viral antigen
Other intervention name(s): Typherix; Havrix
Intervention MeSH terms: Vaccines
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Salmonellosis; typhoid vaccine; enteric fever