Compared with confirmed rubella, a higher proportion of persons with measles IgM reported having fever (92% and 100%, respectively), runny nose (86% and 100%), cough (73% and 100%), or red eyes (67% and 90%) currently or within the previous 28 days; compared with confirmed measles, a higher proportion of persons with rubella IgM reported a history of swollen glands (35% and 81%, respectively). This evidence concerns the gene CD40LG and rubella.