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 ...