Ten group 2 subjects, who had received at least one further booster of an adjuvanted vaccine between T2 and T3, except for MMR vaccine, were compared with 10 group 1 subjects, who did not have received any further booster in the period T2–T3; the ratio T3/T2 of antibodies addressed against measles, mumps and rubella was compared in the subjects of the two groups. This evidence concerns the gene MRC1 and rubella.