They spread when germs pass from an infected person to the nose or throat of others.
Pregnant women can lose their babies.
Vaccination is the best way to protect again measles, mumps, and rubella. Because most children get the MMR vaccines, there are now many fewer cases of these diseases. There would be many more cases if we stopped vaccinating children. Most children should have a total of 2 MMR vaccines. Most doctors recommend that almost all young children get MMR vaccine.