Immunogenicity study of an inactivated bivalent whole cell oral cholera vaccine among Rohingya Myanmar Nationals (adults and children)

Cholera, an acute watery diarrheal disease, caused by toxigenic strains of the bacterium Vibrio cholerae O1 and O139, causes an estimated over 2.9 million cases and over 95,000 deaths annually in cholera endemic countries alone and frequent epidemics in other settings with poor water and sanitation infrastructure. Global estimates range from 1.4-4.8 million cases and 28,000 – 142,000 deaths every year 1. The disease is characterized by acute onset watery diarrhea leading to rapid dehydration and death, if not promptly treated.

Recently a conflict has been conducted in the Rakhine province of Myanmar. During this conflict over 500,000 Rohingya refugees (URMN) have recently been displaced and entered into Cox’s Bazar district in Bangladesh. Among newly arrived displaced people, 60% are women and children living in conditions where public health facilities are lacking. These people are probably not primed and exposed to cholera and the prevailing conditions are high risk for cholera. In the recent past, e.g in Yemen, South Sudan, Haiti and other countries, lack of WaSH and public health facilities have led to large epidemics with high numbers of cholera cases and death. Considering this risk assessment international co-ordination group (ICG) of WHO allocate 900,000 oral cholera vaccines from WHO stockpile to deploy among the refugees.

The prevention of cholera has become a high priority in the global community. Immunization with OCV is the most effective means of preventing cholera infection and its consequence. The World Health Organization (WHO) has warned of a growing risk of a cholera epidemic at makeshift refugee camps in Bangladesh where hundreds of thousands of Myanmarese Rohingya Muslim refugees are sheltered in dire conditions. The camps did not have safe drinking water and lacked sufficient hygiene; filthy water and feces flowed openly through the camps. Risk of waterborne diseases is high, especially there is very high risk of cholera in these camp. Interventions like vaccination are being scaled-up as the situation remains critical and challenging.

The study of ShanChol OCV on Unregistered Myanmar Nationals (URMN) in children and adults will be able to give information regarding the safety and immunogenicity of the vaccine in URMN subjects. This information will be important for proceeding with the cholera vaccination in the refugee population of same socioeconomic structure in future.

Hypothesis

Oral Cholera vaccine (OCV) is immunogenic in different age groups of Unregistered Myanmar Nationals (URMN).

Objectives

The objective of this study is to evaluate the immunogenicity of OCV among healthy Unregistered Myanmar Nationals (URMN) in Bangladesh.

Methods

This will be cross sectional study on a total of 226 healthy Unregistered Myanmar Nationals (URMN). There will be three age cohort which will consist of 80 participants for age 1-5 yrs, 63 participants for age 6-17 yrs and 83 for age 18 yrs and above, with a total of 226 participants. Blood will be taken before and after OCV administration.

Outcome measures/variables

To evaluate the immunogenicity of OCV among Unregisterd Myanmar Nationals (URMN).
The immunogenicity component will be measured by assessing the sero-conversion rate of vibriocidal antibodies after vaccination with OCV to Vibrio cholerae O1.

Cholera, an acute watery diarrheal disease, caused by toxigenic strains of the bacterium Vibrio cholerae O1 and O139, causes an estimated over 2.9 million cases and over 95,000 deaths annually in cholera endemic countries alone and frequent epidemics in other settings with poor water and sanitation infrastructure. The disease is characterized by acute onset watery diarrhea leading to rapid dehydration and death, if not promptly treated.

Among newly arrived displaced people, 60% are women and children living in conditions where public health facilities are lacking. These people are probably not primed and exposed to cholera and the prevailing conditions are high risk for cholera. In the recent past, e.g in Yemen, South Sudan, Haiti and other countries, lack of WaSH and public health facilities have led to large epidemics with high numbers of cholera cases and death.

The study of ShanChol OCV on FDMN in children and adults will be able to give information regarding the safety and immunogenicity of the vaccine in URMN subjects. This information will be important for proceeding with the cholera vaccination in the refugee population of same socioeconomic structure in future.

Therefore, the objective of this study is to evaluate the immunogenicity of OCV among healthy Forcibly Displaced Myanmar Nationals (FDMN) in Bangladesh.

By evaluating the immune responses of OCV among Forcibly Displaced Myanmar Nationals (FDMN), we can compare the immune responses between Bangladeshi population and FDMN. We can also assess the sero-conversion rate of vibriocidal antibodies after vaccination with OCV to Vibrio cholerae O1.