In this study, the highest rate of measles and rubella susceptibility was observed in subjects of group B (age range: 15–19 years), who were vaccinated not only with two- doses of mMV at the ages of 9 and 15 months, respectively, but also received an additional dose of MMR vaccine upon school entrance (three doses of measles and one dose of rubella vaccine). Here, MRC1 is linked to measles.