BIAVAX (rubella and mumps virus vaccine live) II is indicated for simultaneous immunization against rubella and mumps in persons 12 months of age or older. A booster is not needed. The vaccine is not recommended for infants younger than 12 months because they may retain maternal rubella and mumps neutralizing antibodies which may interfere with the immune response. Previously unimmunized children of susceptible pregnant women should receive live attenuated rubella vaccine, because an immunized child will be less likely to acquire natural rubella and introduce the virus into the household. Individuals planning travel outside the United States, if not immune, can acquire measles, mumps or rubella and import these diseases to the United States. Therefore, prior to International travel, individuals known to be susceptible to one or more of these diseases can receive either a single antigen vaccine (measles, mumps, or rubella), or a combined antigen vaccine as appropriate. However, M-M-R* II (Measles, Mumps, and Rubella Virus Vaccine Live) is preferred for persons likely to be susceptible to mumps and rubella; and if single-antigen measles vaccine is not readily available, travelers should receive M-M-R II (Measles, Mumps, and Rubella Virus Vaccine Live) regardless of their immune status to mumps or rubella. Non-Pregnant Adolescent and Adult Females Immunization of susceptible non-pregnant adolescent and adult females of childbearing age with live attenuated rubella virus vaccine is indicated if certain precautions are observed (see below and PRECAUTIONS). Vaccinating susceptible postpubertal females confers individual protection against subsequently acquiring rubella infection during pregnancy, which in turn prevents infection of the fetus and consequent congenital rubella injury. Women of childbearing age should be advised not to become pregnant for three months after vaccination and should be informed of the reasons for this precaution.** It is recommended that rubella susceptibility be determined by serologic testing prior to immunization.*** If immune, as evidenced by a specific rubella antibody titer of 1:8 or greater (hemagglutination-inhibition test), vaccination is unnecessary. Congenital malformations do occur in up to seven percent of all live births. Their chance appearance after vaccination could lead to misinterpretation of the cause, particularly if the prior rubella-immune status of vaccinees is unknown. Postpubertal females should be informed of the frequent occurrence of generally self-limited arthralgia and/or arthritis beginning 2 to 4 weeks after vaccination (see ADVERSE REACTIONS ). Postpartum Women It has been found convenient in many instances to vaccinate rubella-susceptible women in the immediate postpartum period. (See Nursing Mothers ). Revaccination: Children vaccinated when younger than 12 months of age should be revaccinated. Based on available evidence, there is no reason to routinely revaccinate persons who were vaccinated originally when 12 months of age or older. However, persons should be revaccinated if there is evidence to suggest that initial immunization was ineffective. Use with other Vaccines Routine administration of DTP (diphtheria, tetanus, pertussis) and/or OPV (oral poliovirus vaccine) concomitantly with measles, mumps and rubella vaccines is not recommended because there are insufficient data relating to the simultaneous administration of these antigens. However, the American Academy of Pediatrics has noted that in some circumstances, particularly when the patient may not return, some practitioners prefer to administer all these antigens on a single day. If done, separate sites and syringes should be used for DTP and BIAVAX (rubella and mumps virus vaccine live) II. BIAVAX (rubella and mumps virus vaccine live) II should not be given less than one month before or after administration of other virus vaccines. *Registered trademark of MERCK & CO., INC. **NOTE: The Immunization Practices Advisory Committee (ACIP) has recommended "In view of the importance of protecting this age group against rubella, reasonable precautions in a rubella immunization program include asking females if they are pregnant, excluding those who say they are, and explaining the theoretical risks to the others." ***NOTE: The Immunization Practices Advisory Committee (ACIP) has stated "When practical, and when reliable laboratory services are available, potential vaccinees of childbearing age can have serologic tests to determine susceptibility to rubella. . . . However, routinely performing serologic tests for all females of childbearing age to determine susceptibility so that vaccine is given only to proven susceptibles is expensive and has been ineffective in some areas. Accordingly, the ACIP believes that rubella vaccination of a woman who is not known to be pregnant and has no history of vaccination is justifiable without serologic testing."