Effectiveness of a Bivalent Killed Whole Cell Based Oral Cholera Vaccine
Recruitment status was: Recruiting
|Study Design:||Observational Model: Case Control
Time Perspective: Retrospective
|Official Title:||Effectiveness of a Bivalent, Killed Whole-cell Based Oral Cholera Vaccine(Shanchol®) Delivered Through Community-based Mass Vaccination Campaign in a High-risk Population in India: Matched Case-control Studies|
- Vaccine protective effectiveness at individual level [ Time Frame: 11 months ]Matched controls will be selected among the persons of the same age group as that of each case. 1 to 4 ratio will be used in matching cases to controls.Information on all other exposure variables will be collected through questionaire interview for both cases and controls."Protective effectiveness (PE) (%) = [1- the odds of vaccination among cholera confirmed cases relative to the odds of vaccination among matched controls] × 100" is the metric to measure vaccine protective effectiveness at individual level.
- Population level effectiveness (herd effect) [ Time Frame: 11 months ]
Indirect effect: Fraction of household members who are vaccinated in households of unvaccinated cases compared with fraction of household members who are vaccinated in households of unvaccinated controls
Total effect: Fraction of household members who are vaccinated in households of vaccinated cases compared with the fraction of household members who are vaccinated in households of vaccinated controls.
Overall effects: Fraction of household members who are vaccinated in household of cases compared with fraction of household members who are vaccinated in control households.
- Cohort / GIS study for the measure of herd protection [ Time Frame: 11 months ]Geographic unit as a cluster for evaluating vaccine herd protection with the use of cohort analysis, using GIS information from the baseline census. Here, there will be comparison in the incidence of the target outcome (cholera or non-cholera diarrhea) according to the level of vaccine coverage of the geographic unit.
Biospecimen Retention: Samples Without DNA
|Study Start Date:||March 2013|
|Estimated Study Completion Date:||March 2014|
|Estimated Primary Completion Date:||February 2014 (Final data collection date for primary outcome measure)|
Cholera cases group
"Any diarrheal cases or suspected cholera cases from study area, whose stool specimen collected in study health center and examined in reference laboratory, reveals V. cholerae serotype O1/O139 is defined as cholera case"
"A randomly selected age matched individual, who have been living in the study area and did not seek care for diarrheal illness in the study health center since vaccination is defined as control"
The overall goal of this study is to evaluate the protective effectiveness of one or two doses of modified, bivalent, killed whole cell based OCV, given at least 14 days apart, when delivered through community - based mass vaccination campaign using existing public health infrastructure in a high - risk population in Satyabadi block of Puri district, Orissa, India.
This study has following objectives
* To evaluate the individual level protective effectiveness of one or two doses of OCV against culture confirmed cholera episodes, severe enough to seek a formal health care.
- To evaluate population - level effectiveness (herd effects)of OCV delivered through a community based mass vaccination when the vaccine is delivered to more than half of population at risk.
- To determine inverse correlation between vaccine coverage and cholera incidence among diverse geographical clusters.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01508507
|Regional Medical Research Center|
|Chandrashekharpur, Bhubaneswar, Odisha, India, 751016|
|Principal Investigator:||Shantanu K Kar, MD||Director, Regional Medical Research Center, Bhubanewar, Orissa, India|
|Principal Investigator:||Thomas F Wierzba, PHD||International Vaccine Institute|