Cholera Vaccine Investment Strategy in Bangladesh
Condition: Cholera
MeSH terms: Cholera
Study type: Observational

Summary: 
      To evaluate the preventive impact, demand, acceptability, uptake, feasibility, and
      cost-effectiveness of a two-dose regimen of the OCV Shanchol in children living in urban
      slums in Bangladesh, Investigators will conduct a targeted mass immunization programme, using
      an innovative approach successfully deployed by the Bangladesh government in its recent
      countrywide campaign of MR vaccination of 52 million children aged 9 months to 14 years (<15
      years). Investigators will undertake a census of a geographic population of approximately
      300,000 persons, with GIS locations of each household. This census will be updated every 6
      months during the follow-up period to permit tracking of births, deaths, and migrations,
      including changes in location of each individual's residence. Following the initial census,
      the OCV will be offered to all non-pregnant individuals aged 1 to 14 years. Operational
      research and economic studies will evaluate the coverage, feasibility, acceptability, demand,
      costs and cost-effectiveness of this vaccination programme.
    

Detailed description: 
      Burden: Cholera remains a major global problem, resulting in more than 100,000 deaths and
      several million cases annually , mostly children. Vaccination has been reconsidered as a key
      component of the public health response to cholera. Bangladesh has one of the world's highest
      burdens of endemic cholera, with an estimated 300,000 cholera cases and over 4,500 deaths
      annually, and with high caseloads and frequent outbreaks in more than half of the country.
      The endemicity of cholera in Bangladesh is demonstrated by the predictable yearly occurrence
      of the disease in the country's high-risk districts and the repetitive seasonal pattern of
      cholera outbreaks, either in spring or autumn, or both .

      Knowledge gap: More evidence is needed to address uncertainties around the cholera disease
      burden, as well as the impact, feasibility, and cost-effectiveness of various vaccination
      strategies against cholera, to add to the existing knowledge base. A special need for
      acquiring field evidence of these vaccine attributes in settings with endemic cholera, which
      account for a very large fraction of the global cholera disease burden, is also recognized .

      Relevance: Nonetheless, the assertion that selective vaccination of children with OCV is an
      impactful approach to controlling cholera at the population level rests on unproven
      assumptions, since there are no studies that directly address this vaccination strategy.
      Therefore, further study on whether targeted mass immunization can create efficiencies that
      general mass immunization would not, is warranted. The Investigators therefore believe that
      the most compelling question for the control of endemic cholera in Bangladesh is how
      targeting 1-14 year olds in urban slums, using the established platform of targeted mass
      childhood immunization recently deployed by the GOB for measles-rubella (MR) vaccine, impacts
      on the overall burden of cholera in the population and how feasible and cost-effective this
      strategy is. Addressing these questions will add to the evidence base on the most cost
      efficient and effective settings and strategies for use of OCV to control endemic disease and
      optimize health impact.

      Hypothesis : Vaccination of children under 15 years of age in urban slums of Dhaka will
      confer at least 50% overall protection to the entire population through combined direct and
      indirect protective effects and it will be cost effective.

      Objectives:To evaluate the feasibility, efficiency, and impact of a two-dose regimen of the
      oral cholera vaccine (OCV) Shanchol delivered to children aged 1-14 years residing in urban
      slums, leveraging a targeted mass immunization delivery platform used for other vaccines in
      Bangladesh.

      Methods: Observational design based on the contrast of persons who do and do not get
      vaccinated according to public health practice(Age-targeted mass immunization program).
    

Intervention name(s): Shanchol
Intervention type(s): Biological
Intervention description(s): Oral Cholera Vaccine
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        The study population will be recruited from different wards of Dhaka city corporation
        (wards 42, 43, 45, 46, 47, 48, 58, 91 and 92 which are now numbered as 29,30,32,33,34 of
        Dhaka North City Corporation and 14,22,55,56,57 of Dhaka South City Corporation
        respectively).
      
Biospecimen description: 
      Specimens will be preserved for 5 years for future use.
    
Keywords: Cholera; Vaccine; Strategy