Protective efficacy of oral whole-cell/recombinant-B-subunit cholera vaccine in Peruvian military recruits

• Published in: The Lancet (British edition) Vol. 344; no. 8932; pp. 1273 - 1276
• Main Authors: Sanchez, J.L, Vasquez, B, Begue, R.E, Meza, R, Castellares, G, Cabezas, C, Watts, D.M, Svennerholm, A-M, Sadoff, J.C, Taylor, D.N
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 05.11.1994; Lancet; Elsevier Limited
• Subjects: ABO Blood-Group System; Administration, Oral; Adolescent; Adult; Adults; Bacteria; Bacterial diseases; Biological and medical sciences; Blood group O; Blood groups; Cholera; Cholera - blood; Cholera - epidemiology; Cholera - microbiology; Cholera - prevention & control; Cholera Vaccines; Diarrhea; Double-Blind Method; Double-blind studies; E coli; Effectiveness; Efficacy; Epidemics; Follow-Up Studies; Human bacterial diseases; Humans; Immunization; Immunization Schedule; Incidence; Infectious diseases; Lymphocytes B; Male; Medical research; Medical sciences; Middle Aged; Military; Military Personnel; Peru; Peru - epidemiology; Population studies; Public health; Recruits; Serotyping; Tropical bacterial diseases; Tropical medicine; Vaccines; Vaccines, Inactivated; Vaccines, Synthetic; Vibrio cholerae - classification; Waterborne diseases; South America; Peru; America; Infection; Human; Prevention; Immunoprophylaxis; Vibrio cholerae; Oral administration; Bacteriosis; Bacteria; Vibrionaceae; Cholera; Vaccine
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(94)90755-2

Summary The cholera epidemic in South America has reinforced the need for safe and effective oral vaccines. In a randomised, double-blind, placebo-controlled efficacy trial among 1563 Peruvian military recruits we have investigated the protective efficacy of an oral inactivated whole-cell/recombinant-B-subunit (WC/rBS) cholera vaccine. Participants were given two oral doses of cholera vaccine or Escherichia coli K12 placebo, with an interval of 7-14 days. 1426 (91%) subjects received the two prescribed doses and were followed up for a mean of 18 weeks (median 21 weeks). After vaccination, Vibrio cholerae 01 El Tor Ogawa was isolated from 17 subjects with diarrhoea. 16 of the cholera cases occurred 2 weeks or longer after the second dose of vaccine (14 placebo recipients, 2 vaccinees). We also detected 14 symptomless infections (11 [7 placebo recipients, 4 vaccinees]) 2 weeks or longer after the second dose. The vaccine had significant protective efficacy against cholera (86% [95% Cl 37-97], p<0·01) but not against symptomless infection (42% [-96 to 85]). All cholera cases were in people of blood group O, who made up 76% of the study population (p<0·01). Two doses of WC/rBS vaccine, given 1 to 2 weeks apart, provide rapid, short-term protection against symptomatic cholera in adult South Americans, who are predominantly of blood group O. Long-term efficacy studies in Peruvian adults and children are under way.