RESUMO
A controlled field trial comparing the effectiveness of a plain cholera vaccine with that of a vaccine adsorbed to aluminium hydroxide was carried out in a cholera-endemic area of Indonesia during 1973-75. Tetanus toxoid adsorbed to aluminium phosphate was used as the control. In vaccinees aged 1-4 years, the adsorbed cholera vaccine provided about 88% protection for 6 months following vaccination and still provided about 50% protection between 11 and 14 months after vaccination. In the same age group, the plain vaccine provided only 53% protection during the first 6 months and no appreciable protection beyond that period. In those aged 5 years and over, both vaccines provided 50-60% protection throughout the period of observation (14 months). Neither vaccine caused any serious side effects.