Before Receiving This Vaccine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For measles, mumps, and rubella vaccine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to measles, mumps, and rubella vaccine, to the antibiotic neomycin, to gelatin, or to eggs. Also tell your health care professional if you are allergic to any other substances, such as preservatives.

Pregnancy—Tell your doctor if you are pregnant or if you may become pregnant within 3 months after receiving this vaccine. Although adequate studies have not been done in either humans or animals and problems have not been shown to occur, use of measles, mumps, and rubella vaccine during pregnancy, or becoming pregnant within 3 months after receiving the measles, mumps, and rubella vaccine, is not recommended. Because the natural measles infection has been shown to increase the chance of birth defects and other problems, it is thought that the live virus vaccine may cause similar problems. Mumps vaccine may infect the placenta, although the vaccine has not been shown to infect the fetus or to cause birth defects. Rubella vaccine crosses the placenta. However, the Centers for Disease Control observed more than 200 women who received the vaccine within 3 months before or after becoming pregnant and those women gave birth to normal babies.

Breast-feeding—Mothers who are receiving measles, mumps, and rubella vaccine and who wish to breast-feed should discuss this with their doctors, because rubella vaccine virus may pass into the breast milk and may cause mild rubella infection in nursing babies. However, studies have not shown that this infection causes any serious problems.

Children—Use is not recommended for infants younger than 12 months of age, unless the risk of measles infection is high. Waiting until children are at least 12 months of age is important because antibodies that infants receive from their mothers before birth may interfere with the effectiveness of the vaccine. There may be special reasons why children between 6 months and 12 months of age also may require measles vaccination.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Before you receive measles, mumps, and rubella vaccine, it is especially important that your health care professional know if you have received any of the following:

• Cancer medicines or
• Radiation therapy—May reduce the useful effect of the vaccine

Other medical problems—The presence of other medical problems may affect the use of measles, mumps, and rubella vaccine. Make sure you tell your doctor if you have any other medical problems, especially:

• Immune deficiency condition (or family history of)—Condition may increase the chance of developing side effects and the severity of side effects of the vaccine and/or may decrease the useful effects of the vaccine

• Severe illness with fever—The symptoms of the condition may be confused with the possible side effects of the vaccine