Safety of An Oral O1 / O139 Cholera Vaccine (Enteric Capsules)
Condition: Safety of the Oral O1 / O139 Cholera Vaccine (Enteric Capsules)
MeSH terms: Cholera
Study type: Interventional
Phase: Phase 1

Summary: 
      Cholera is an acute enteric infectious disease caused by the bacterium Vibrio cholera,
      leading to watery diarrhea and loss of fluids from the small intestines. The World Health
      Organization (WHO) estimates that up to 4.3 million cholera cases annually with more than
      100,000 of them result in death in worldwide. Cholera is mainly caused by the O1 or O139
      serogroups of V. cholera. Vaccination has been shown to be a cost-effective, more immediate
      option for cholera control and prevention. Injectable vaccine is not recommended by the World
      Health Organization (WHO) mainly because of its limited efficacy and short duration of
      protection. However, the inactivated whole-cell, bivalent O1 and O139 cholera vaccine have
      provided evidence of substantial protective efficacy. With the goal of making an ideal
      low-cost OCV that could be used in cholera-endemic countries, a phase I trial was conducted
      to estimate safety of the oral O1 / O139 cholera vaccine (enteric capsules).
    

Detailed description: 
      Cholera is an acute enteric infectious disease caused by the bacterium Vibrio cholera,
      leading to watery diarrhea and loss of fluids from the small intestines. The disease can
      quickly lead to severe dehydration and death without proper and timely management. The World
      Health Organization (WHO) estimates that up to 4.3 million cholera cases annually with more
      than 100,000 of them result in death in worldwide. The high morbidity and consequent
      mortality caused by cholera is attributable to several factors, including lack of access to
      safe drinking water, poor sanitation and poor hygiene practices and transmitted via the
      fecal-oral route by ingesting food or water contaminated with the bacterium. Cholera is a
      significant public health issue in many developing countries in Africa, Southeast Asia, the
      Caribbean, and South America, and is rare in industrial countries with most cases occurring
      in travelers who have visited cholera-affected areas.

      Cholera is mainly caused by the O1 or O139 serogroups of V. cholerae among the more than 200
      V. cholerae serogroups, O1 strains are divided into two biotypes: Classical and El Tor. Each
      biotype can be further divided into 3 serotypes: Inaba, Ogawa, Hikojima. V. cholerae O1 has
      been shown to be responsible for the first six cholera pandemics. In 1992, a new V. cholerae
      serogroup O139 emerged and it has caused epidemics that spanned most of Asia. This strain was
      a genetic derivative of El Tor biotype in which the O1 biosynthetic genes were replaced by
      the O139 biosynthetic genes. Both V. cholerae O1 and O139 can produce an enterotoxin, which
      causes serious diarrhea, causing dehydration, and can lead to death in a few days.

      Vaccination has been shown to be a cost-effective, more immediate option for cholera control
      and prevention. Injectable vaccine is not recommended by the World Health Organization (WHO)
      mainly because of its limited efficacy less than 50% and short duration of protection almost
      no more than six months. Enteric vaccination has already been regarded as the most effective
      approach to control such illnesses as well as to prevent cholera in endemic countries. The
      inactivated whole-cell, bivalent O1 and O139 cholera vaccine have provided evidence of
      substantial protective efficacy up to 60% at least 3-5 years. In 2011 the first low-cost oral
      cholera vaccine for international use was given prequalification by the World Health
      Organization (WHO). With the goal of making an ideal low-cost OCV that could be used in
      cholera-endemic countries, a phase I trial was conducted to estimate safety of the oral O1 /
      O139 cholera vaccine (enteric capsules), in order to fulfill the requirements of WHO. On the
      other hand, China is a non-endemic country of cholera, it will also can provided a safe and
      convenient vaccine for the travellers who visited cholera-affected areas.
    

Intervention name(s): The oral O1 / O139 cholera vaccine (enteric capsules)
Intervention type(s): Biological
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention