title: Effectiveness of an oral cholera vaccine campaign to prevent clinically-significant cholera in Odisha State, India.
abstract: BACKGROUND
  A clinical trial conducted in India suggests that the oral cholera vaccine, Shanchol, provides 65% protection over five years against clinically-significant cholera. Although the vaccine is efficacious when tested in an experimental setting, policymakers are more likely to use this vaccine after receiving evidence demonstrating protection when delivered to communities using local health department staff, cold chain equipment, and logistics.
  
  
  METHODS
  We used a test-negative, case-control design to evaluate the effectiveness of a vaccination campaign using Shanchol and validated the results using a cohort approach that addressed disparities in healthcare seeking behavior. The campaign was conducted by the local health department using existing resources in a cholera-endemic area of Puri District, Odisha State, India. All non-pregnant residents one year of age and older were offered vaccine. Over the next two years, residents seeking care for diarrhea at one of five health facilities were asked to enroll following informed consent. Cases were patients seeking treatment for laboratory-confirmed V. cholera-associated diarrhea. Controls were patients seeking treatment for V. cholerae negative diarrhea.
  
  
  RESULTS
  Of 51,488 eligible residents, 31,552 individuals received one dose and 23,751 residents received two vaccine doses. We identified 44 V. cholerae O1-associated cases and 366 non V. cholerae diarrhea controls. The adjusted protective effectiveness for persons receiving two doses was 69.0% (95% CI: 14.5% to 88.8%), which is similar to the adjusted estimates obtained from the cohort approach. A statistical trend test suggested a single dose provided a modicum of protection (33%, test for trend, p=0.0091).
  
  
  CONCLUSIONS
  This vaccine was found to be as efficacious as the results reported from a clinical trial when administered to a rural population using local health personnel and resources. This study provides evidence that this vaccine should be widely deployed by public health departments in cholera endemic areas.
authors: International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: twierzba@path.org.
authors: Thomas F
authors: TF
authors: Wierzba
authors: Regional Medical Research Center (ICMR), Chandrasekharpur, Bhubaneswar 751-023, Odisha, India.
authors: Shantanu K
authors: SK
authors: Kar
authors: International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors: Vijayalaxmi V
authors: VV
authors: Mogasale
authors: Regional Medical Research Center (ICMR), Chandrasekharpur, Bhubaneswar 751-023, Odisha, India.
authors: Anna S
authors: AS
authors: Kerketta
authors: International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors: Young Ae
authors: YA
authors: You
authors: Directorate of Health Services, Bhubaneswar, Odisha, India.
authors: Prameela
authors: P
authors: Baral
authors: Regional Medical Research Center (ICMR), Chandrasekharpur, Bhubaneswar 751-023, Odisha, India.
authors: Hemant K
authors: HK
authors: Khuntia
authors: International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: mali25@jhu.edu.
authors: Mohammad
authors: M
authors: Ali
authors: International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: yanghee.kim33@gmail.com.
authors: Yang Hee
authors: YH
authors: Kim
authors: Regional Medical Research Center (ICMR), Chandrasekharpur, Bhubaneswar 751-023, Odisha, India.
authors: Shyam Bandhu
authors: SB
authors: Rath
authors: International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors: Anuj
authors: A
authors: Bhattachan
authors: International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors: Binod
authors: B
authors: Sah
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002771:Cholera / Q000453:epidemiology* / Q000517:prevention & control*; D022121:Cholera Vaccines / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D022121:Cholera Vaccines
keywords: Cholera; Diarrhea; Effectiveness; India; Vaccine