A prospective study was designed to evaluate the serologic efficacy of a two dose meas les vaccination schedule, at 6 months and 11 months of age. Infants were given a further attenuated measles virus vaccine (BIKEN CAM 70, Fundação Oswaldo Cruz) and serum samples were tested for measles antibodies using the indirect immunofluorescence technique (IFA) and ELISA. Seroconversion rates 6 to 12 months (mean of 8.0 ±1.7 months) following the second dose of measles vaccine were 88.5% (85/96) by IFA and 96.8% (93/96) by ELISA. No measles cases were reported during the study period. In regions where a significant proportion of measles cases occurs before nine months of age, vaccination with a two doses schedule, at 6 and 11 months of age, may represent an alternative for measles control.