Abstract
A total of 250 adult cows and 13 (young) heifers, all seronegative for brucellosis, were vaccinated with a reduced dose (3 × 109) Strain 19 (S‐19) vaccine. Twelve months after vaccination all cattle were negative to the serological tests. The results obtained are similar to those found by other authors and support the use of reduced dose S19 under the heat conditions found in Zambia.