Cholera vaccine(International Centre for Diarrhoeal Disease Research, Bangladesh)

Concomitant administration of multiple vaccines, including live attenuated immunizations, is safe and effective. Some restrictions apply for live vaccines; administering a live-virus vaccine within 4 weeks after administration of another live-virus vaccine can decrease immunogenicity to the second administered vaccine. Thus, it is recommended that live-virus vaccines should be administered the same day or ≥4 weeks apart. Data on co-administration of the currently available whole-cell killed Oral Cholera Vaccine (OCVs) with other oral vaccines, specifically, oral polio vaccines (OPV) is lacking. Although the risk of immunological interference due to co-administration of live vaccines with non-live vaccines is considered small if at all, a theoretical concern of interference has been raised. Given the substantial geographic correlation between polio- and cholera-affected and at-risk areas, which include some of the world's most impoverished and hard-to-reach populations, a strategy of co-administration of OCV with OPV to children targeted to receive OPVs has the potential to optimize the use of limited resources and improve coverage for both vaccines. The manufacturer recommendation for a two-week interval between administration of OPV and OCV precludes an integrated campaign or routine use in which OCV could be co-administered with OPV.

Cholera, a rapidly dehydrating watery diarrheal disease transmitted through water or food contaminated with the bacterium, Vibrio cholerae, is a major cause of morbidity and mortality in low income countries like Bangladesh. In our country, Cholera disease burden consists of both cholera outbreaks and endemic cholera comprising at least 300,000 severe cases and 1.2 million infections each year. To combat this situation, Vaccination against cholera has been proved effective both in endemic and epidemic settings. But, the WHO recommended Dukoral and Prequalified Shanchol are quite expensive for our country perspective. Therefore, locally manufactured OCV can improve the cost effectiveness and make it affordable for all. The hypothesis of this proposal is that Locally produced orally administered whole cell inactivated HL-OCV test formulations A and B are safe and immunogenic in adults and children in Bangladesh as compared to ShancholTM. The results of the study will allow us to understand the safety and immunogenicity outcome of the HL-OCV compared to Shanchol vaccine. The total sample size will be 840 healthy participants. 840 healthy participants (360 adults, 240 Children and Adolescent and 240 young children) of 18-45 years, 5- less than 18 years and 1 year to less than 5 years will be enrolled in the study. Children whose parents/guardians give voluntary consent will be enrolled in the study. The investigators will provide 2 dose of vaccine for three groups in 14 days interval. Test formulations will be locally manufactured and the comparator group will get Shanchol. The Investigators propose to collect three blood samples (Day 0, 14 and 28).