風疹, also known as rubella, is a contagious viral infection characterized by a mild rash and fever. It is caused by the rubella virus and is typically spread through respiratory droplets when an infected person coughs or sneezes. While it often causes mild symptoms in children and adults, it can lead to serious complications during pregnancy, including birth defects. Vaccination is the most effective way to prevent 風疹. The MMR vaccine, which protects against measles, mumps, and rubella, is commonly administered to children. Public health efforts aim to increase vaccination rates to control outbreaks and protect vulnerable populations, especially pregnant women.