measles and rubella virus vaccine, live, attenuated
M-R-Vax II

Available forms
Available by prescription only
Injection: Single-dose vial containing not less than 1,000 TCID₅₀ (tissue culture infective doses) each of attenuated measles virus derived from Enders’ attenuated Edmonston strain (grown in chick embryo culture) and the Wistar RA 27/3 strain of rubella virus (propagated in human diploid cell culture)
 Note: 10-dose and 50-dose vials are available to government agencies and institutions.

Indications and dosages
 Measles and rubella immunization. Adults and children age 15 months and older: 0.5 ml in outer aspect of the upper arm. For adequate protection against measles, a two-dose schedule is recommended (at least 1 month between doses).

Pharmacodynamics
Measles and rubella prophylactic action: Vaccine promotes active immunity to measles (rubeola) and German measles (rubella) virus by inducing production of antibodies.

Pharmacokinetics
Absorption: Antibodies are usually detectable 2 to 3 weeks after injection. Duration of vaccine-induced immunity is expected to be lifelong.
Distribution: No information available.
Metabolism: No information available.
Excretion: No information available.

Contraindications and precautions
Contraindicated in immunosuppressed patients; in those with cancer, blood dyscrasias, gamma globulin disorders, fever, active untreated tuberculosis, or anaphylactic reactions to eggs or neomycin; in those receiving corticosteroid or radiation therapy; and in pregnant women. Use cautiously in patients with history of cerebral injury, individual or family history of seizures, or any other condition in which stress resulting from fever should be avoided.

Interactions
Drug-drug. Immune serum globulin, transfusions of blood or blood products: May interfere with immune response to vaccine. Whenever possible, defer vaccination for 3 months in these situations.
Immunosuppressants: May interfere with response to vaccine. Avoid use together if possible.

Adverse reactions
CNS: syncope, malaise, headache, fever.
CV: vasculitis.
EENT: sore throat.
GI: vomiting, diarrhea.
Respiratory: cough.
Skin: rash; erythema, burning, or stinging at injection site.
Other: lymphadenopathy, anaphylaxis.

Effects on lab test results
None reported.

Overdose and treatment
No information available.

Special considerations
• Drug can be given to patient with HIV infection who doesn’t have severe immunosuppression.
• Obtain a thorough history of allergies, especially to antibiotics, eggs, chicken, or chicken feathers, and of reactions to immunizations.
• Skin testing is needed to assess vaccine sensitivity (against a control of normal saline solution in the opposing limb) in patients with history of anaphylactoid reactions to eggs. Administer a prick (intracutaneous) or scratch test with a 1:10 dilution. Read results after 5 to 30 minutes. A positive reaction is a wheal with or without pseudopodia and surrounding erythema.
• Have epinephrine solution 1:1,000 available to treat allergic reactions.
• Don’t give drug I.V. Use a 25G, 5/8-inch needle and inject S.C., preferably into the outer aspect of the upper arm.
• Use a sterile syringe free of preservatives, antiseptics, and detergents for each injection because these substances may inactivate the live virus vaccine.
• Use only diluent supplied. Discard reconstituted solution after 8 hours.
• Solution may be used if red, pink, or yellow, but it must be clear.
• Don’t give vaccine less than 1 month before or after immunization with other live-virus vaccines, except for mumps virus vaccine and monovalent or trivalent live oral poliovirus vaccine, and poliovirus vaccine, inactivated, which may be given simultaneously.
• Vaccine may not offer protection when given within a few days’ exposure to natural measles or rubella.
• According to Centers for Disease Control and Prevention recommendations, measles, mumps and rubella (MMR) is the preferred vaccine.
• Passive immunization is given with immune serum globulin when immediate protection against measles is required in patients who can’t receive the measles vaccine component. Don’t give either vaccine component simultaneously with immune serum globulin.
• Store vaccine at 36° to 46° F (2° to 8° C) and protect from light.
• Revaccination is usually given between ages 4 and 6 years. Measles virus vaccine, live, MMR II, or MR-VAX II may be used.
• Measles and rubella vaccine may temporarily decrease response to tuberculin skin testing. If a tuberculin skin test is needed, give it either before or simultaneously with measles and rubella vaccine.
Breast-feeding patients
• No data are available regarding distribution of measles and rubella virus components in breast milk. Rubella virus or virus antigen may appear in breast milk in about 68% of patients. Few adverse effects have been linked to breast-feeding after immunization with rubella-containing vaccines. The risk-benefit ratio suggests that breast-feeding women may be immunized with the rubella component, if needed.
Pediatric patients
• Children younger than age 15 months may not respond to one or both of the vaccine components because retained maternal antibodies may interfere with the immune response; revaccination is recommended after age 15 months.

Patient education
• Tell patient to expect tingling sensations in the limbs or joint aches and pains that may resemble arthritis, beginning several days to several weeks after vaccination. These symptoms usually resolve within 1 week. Other effects include pain and inflammation at the injection site and a low-grade fever, rash, or difficulty breathing. Recommend acetaminophen for relief of fever.
• Encourage patient to report distressing adverse reactions.
• Advise women of childbearing age not to become pregnant for 3 months after receiving the vaccine.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use