In addition to vaccine, another source of protection for young infants is their mother's anti-measles antibody which the fetus gets transplacentally and lasts until about 9 months of age.

除了疫苗，对幼婴的另一种保护措施是来自母亲的抗麻疹免疫球蛋白，胎儿经胎盘获得并可持续到大约9个月大。