Measles, mumps, and rubella immunization in adults

INTRODUCTION — The combination measles, mumps, and rubella (MMR) vaccine includes live virus vaccines against measles, mumps, and rubella; it is an important tool for preventing serious illness due to these infections [1,2].

Issues related to the use of combination MMR vaccine in adults will be discussed here; use of MMR immunization in infants, children, and adolescents is discussed separately. (See "Measles, mumps, and rubella immunization in infants, children, and adolescents" and "Standard immunizations for nonpregnant adults".)

Issues related to the epidemiology, clinical manifestations, diagnosis, and management of measles, mumps, and rubella are discussed separately. (See "Measles: Clinical manifestations, diagnosis, treatment, and prevention" and "Mumps" and "Rubella".)

MEASLES, MUMPS, AND RUBELLA INFECTIONS — The measles virus causes an acute infection characterized by fever, cough, coryza, conjunctivitis, rash (picture 1A-B), and enanthem (picture 2) that may be followed by severe complications including encephalitis. Adults with measles are at increased risk of mortality compared with older children, and measles in pregnancy is associated with premature labor and spontaneous abortion [3]. (See "Measles: Clinical manifestations, diagnosis, treatment, and prevention".)

The mumps virus causes an acute infection characterized by parotid swelling (picture 3). Mumps infection usually is self-limited but may be associated with complications including orchitis and oophoritis, aseptic meningitis, and encephalitis. The most serious complications of mumps arise more frequently in adults than in children, including neurologic complications. (See "Mumps", section on 'Clinical manifestations'.)

The rubella virus causes a generally mild acute infection with a characteristic rash (picture 4) that can affect both children and adults. Fetal rubella infection can cause significant congenital anomaly; immunity among adults (particularly women of childbearing age) is essential for elimination of the most important consequences of rubella: congenital rubella syndrome, miscarriage, and fetal death. (See "Rubella", section on 'Clinical manifestations' and "Rubella in pregnancy" and "Congenital rubella", section on 'Clinical features'.)

VACCINE EFFICACY — Routine measles, mumps, and rubella (MMR) immunization is effective in preventing measles, mumps, and rubella infection as indicated by the dramatic decline in the number of cases of measles, mumps, and rubella following the introduction of vaccine programs in the 1960s (figure 1A-C) [1,4]. It is rare for immunocompetent individuals to not be fully immune after two doses of MMR (table 1).

●Measles – Measles vaccination usually leads to long-term immunity. In the United States, measles antibodies develop in 96 percent of individuals vaccinated at age 12 months and in 98 percent of individuals vaccinated at age 15 months [3,5]. For the small percentage of nonresponders to the first vaccine dose, a second dose will result in seroconversion in 90 percent of cases [6], resulting in 99 percent immunity among individuals who have received two doses of measles vaccine [7]. Thus, the second vaccine dose generally provides immunity among nonresponders to the first dose. There are no compelling data to support a routine third dose of MMR vaccine for the prevention of measles [8].

Measles antibody titers have been shown to decrease over time [9-12]. Most people with waning antibody titers after vaccination have an anamnestic response to revaccination, suggesting continued immunity [13]. However, measles can occur in previously vaccinated individuals. As an example, in one study including 232 cases of measles in California between 2000 and 2015, 13 individuals (11 percent) had received ≥2 doses of measles vaccine [14]. These individuals had milder disease. At least one analysis has suggested that waning immunity contributes to lower vaccine efficacy [15].

The evidence for efficacy of MMR vaccine administered as post-exposure prophylaxis for prevention of measles is limited and mixed [16-18]. Prophylactic post-exposure vaccination may provide some protection in settings of limited contact such as schools and daycare centers [1]. The efficacy is likely to be diminished in household settings with intense contact because, in these settings, individuals are exposed for prolonged duration during the prodromal period when the index patient is infectious.

●Mumps – Mumps vaccination seroconversion rates range from 84 to 100 percent [19]. In one study comparing the persistence of cellular and humoral immunity to mumps virus in 50 individuals who had follow-up more than 20 years after receiving two MMR vaccinations during early childhood with a control group who had a history of naturally acquired immunity to mumps, levels of detectable anti-mumps virus immunoglobulin (Ig)G antibodies were lower in the vaccinated group [20]. However, mumps antigen-specific lymphoproliferative responses were detected in 98 percent of all subjects, consistent with long persistence of cellular immunity. Other studies have noted that cellular immune responses to the mumps virus can be identified in the majority of vaccinated individuals, regardless of antibody status [21-23].

A third dose of MMR vaccine may be useful to limit transmission of mumps in outbreak settings that occur in high-density, close-contact settings, given the possibility of two-dose mumps vaccine failure due to waning of vaccine-induced immunity [24,25]. In one mumps outbreak during which 1755 students (80 percent of students in grades 6 to 12) received a third dose of MMR vaccine, mumps attack rates declined from 4.9 percent (three weeks before vaccination) to 0.13 percent (three weeks after vaccination) [25].

●Rubella – One dose of vaccine produces a rubella seroconversion rate of about 95 percent. The durability of antibodies produced by the vaccine and by naturally acquired infection is comparable. Titers of antibody induced by vaccine tend to be lower than those produced by natural infection but are protective against infection. Some individuals have been reported to experience symptomatic or asymptomatic infection despite previous immunization [26,27]. Asymptomatic reinfection usually does not lead to detectable viremia [28].

VACCINE FORMULATIONS — Three formulations of measles, mumps, and rubella–containing vaccines are available in the United States, including one formulation that also provides varicella virus coverage [1]:

●Measles, mumps, and rubella (MMR) combination vaccine – In November of 2022, the United States Advisory Committee on Immunization Practices (ACIP) expanded the options for MMR vaccines to two options (M-M-R II and PRIORIX), both of which contain genetically similar or identical live attenuated measles, mumps, and rubella viruses [29]. Either vaccine is recommended for routine use in individuals ≥12 months of age. The two vaccines are interchangeable.

●Measles, mumps, rubella, and varicella (MMRV) combination vaccine – MMRV is a vaccine that includes live attenuated measles, mumps, rubella, and varicella viruses. It is licensed for use in children 12 months through 12 years of age.

These vaccines contain small amounts of neomycin, and the M-M-R II and MMRV vaccines also contain gelatin [1,29]. They are supplied as a lyophilized (freeze-dried) powder with a separate diluent. Proper storage and handling of powder and diluents are necessary to prevent inactivation of the vaccine viruses [1].

Single-antigen (ie, monovalent) formulations of measles, mumps, and rubella vaccines are not available in the United States [30] but are available in some other countries [31]. An investigational monovalent aerosolized measles vaccine resulted in lower rates of seropositivity than a subcutaneously administered vaccine in a randomized trial in Indian children [32].

INDICATIONS AND SCHEDULES

United States

Who should be immunized

Children — In the United States, routine immunization with measles, mumps, and rubella (MMR) vaccine is recommended for children at 12 to 15 months and 4 through 6 years of age [1,33]. The second dose of MMR can be given as early as 28 days after the first dose, provided that both doses are given at ≥12 months of age [1,33]. In several studies, the median seroconversion rates for measles, mumps, and rubella after one dose of MMR were ≥94 percent; immunity appears to be long-lasting (table 1) [9,10,34-41].

Further details on MMR immunization in children are found elsewhere. (See "Measles, mumps, and rubella immunization in infants, children, and adolescents".)

Adults

General principles — In general, immunity to measles and mumps may be presumed for adults born before 1957; health care workers are an exception (see 'Health care workers' below). In contrast, immunity to rubella is not assured and should be determined by laboratory testing for all women of childbearing age, regardless of birth year. (See "Prenatal care: Initial assessment", section on 'Documentation of rubella immunity'.)

At least one dose of MMR vaccine should be administered to adults born in 1957 or later (who are not included in the categories below), unless there is laboratory evidence of immunity to each of the three viruses (or a medical contraindication to vaccination) [42]. Since it may be difficult to obtain childhood immunization records, a practical strategy endorsed by the American College of Physicians is to immunize all adults born after 1956 [43]. There is no increase in vaccine-associated adverse reactions in people who are already immune to measles, mumps, and/or rubella [3].

For individuals in the following categories, formal documentation of immunity should be established [1]; in the absence of evidence for immunity, two doses of the MMR vaccine should be administered at least 28 days apart (figure 2) (see 'Documenting immunity' below):

●Formal documentation of immunity to measles, mumps, and rubella should be established for adults in the following categories:

•Students in post-secondary educational institutions

•Health care workers (see 'Health care workers' below)

•International travelers

•HIV-infected individuals who do not have current evidence of severe immunocompromise (defined as CD4+ T lymphocyte [CD4] percentage <15 percent or CD4 count <200 cells/microL) (see "Immunizations in persons with HIV", section on 'Measles, mumps, and rubella vaccine')

•Hematopoietic cell transplant (HCT) recipients 24 months following HCT who are no longer receiving immunosuppression and do not have active graft-versus-host disease [44] (see "Immunizations in hematopoietic cell transplant candidates and recipients", section on 'Measles, mumps, and rubella')

●Formal documentation of immunity to measles should be established for:

•Individuals at risk for exposure during an outbreak (see 'Outbreak settings' below and "Measles: Epidemiology and transmission", section on 'Transmission')

•Individuals previously vaccinated with attenuated measles vaccine accompanied by immune globulin or high-titer immune globulin

•Individuals previously vaccinated with killed measles vaccine or vaccine of unknown type between 1963 and 1967

•Close contacts of immunocompromised individuals

●Formal documentation of immunity to mumps should be established for individuals previously vaccinated with killed mumps vaccine or mumps vaccine of an unknown type.

●Formal documentation of immunity to rubella should be established for all women of childbearing age via laboratory testing. If there is no evidence of immunity, women who are not pregnant should be vaccinated. Pregnant women who do not have evidence of immunity should receive MMR vaccine upon completion or termination of pregnancy and before discharge from the health care facility. Repeat testing for serologic evidence of immunity thereafter is not required.

Health care workers — Formal documentation of immunity to measles, mumps, and rubella should be established for health care workers (even those born before 1957) [45,46].

For health care workers who have no laboratory evidence of immunity to measles or mumps (or laboratory confirmation of disease), two doses of MMR should be given at least four weeks apart. If they only lack laboratory evidence of immunity to rubella, at least one dose of MMR should be given [47].

Issues related to post-exposure prophylaxis are discussed below. (See 'Post-exposure prophylaxis' below.)

Health care workers without evidence of immunity who were exposed to an individual with measles should be excluded from the workplace from day 5 through day 21 after exposure. If the case is confirmed, even those who were vaccinated within 72 hours should be excluded [48].

Documenting immunity — Catch-up MMR immunization is necessary for individuals who lack appropriate evidence of immunity or whose MMR immunization status is unknown [1,33]. Evidence of immunity is established by one of the following [1]:

●Documentation of age-appropriate vaccination with a live attenuated vaccine (vaccination reported by a caregiver is not valid without appropriate documentation):

•For measles – Two doses of measles-containing vaccine, both administered at ≥12 months of age, separated by ≥28 days (doses administered before 12 months of age are not counted).

•For mumps – Two doses of mumps-containing vaccine, both administered at ≥12 months of age, separated by ≥28 days (doses administered before 12 months of age are not counted).

•For rubella – One dose of rubella-containing vaccine administered at ≥12 months of age, except for pregnant women who require laboratory evidence of immunity or confirmation of disease.

For individuals who have documented receipt of two doses of MMR, the United States Centers for Disease Control and Prevention does not require an antibody titer to be measured for evidence of measles immunity. Fewer than 1 percent of immunocompetent individuals lack laboratory evidence of immunity after two doses of MMR, although antibody titers may wane over time [13]. (See 'Vaccine efficacy' above.)

●Laboratory evidence of immunity (measles, mumps, and rubella immunoglobulin [Ig]G).

●Laboratory confirmation of measles, mumps, and rubella disease (clinical diagnosis without laboratory confirmation is not sufficient evidence of immunity). (See "Measles: Clinical manifestations, diagnosis, treatment, and prevention", section on 'Diagnosis' and "Mumps", section on 'Diagnosis' and "Rubella", section on 'Diagnosis'.)

●Birth before 1957 – Individuals born before 1957 are generally considered immune to measles and mumps, except health care workers. (See 'Health care workers' above.)

Outbreak settings — Outbreak settings should be managed as follows:

●In a measles outbreak setting, adults who are incompletely immunized against measles should receive two doses of MMR separated by at least 28 days; the initial vaccination should be administered within 72 hours of exposure [1]. This includes unvaccinated health care workers born before 1957 with no laboratory evidence of measles and mumps immunity (or confirmation of disease). (See 'Health care workers' above and "Measles: Epidemiology and transmission", section on 'Outbreak control measures'.)

Individuals unable to produce documentation of measles immunity should be excluded from the outbreak setting until they have complied with vaccination requirements. Those who are exempt from vaccination for medical, religious, or other reasons should be excluded from the outbreak setting for a minimum of three weeks after the onset of rash in the last measles case.

Recommendations for children in an outbreak setting are discussed elsewhere. (See "Measles, mumps, and rubella immunization in infants, children, and adolescents", section on 'International travel and outbreaks'.)

●In a mumps outbreak setting, individuals who are incompletely immunized against mumps should receive two doses of MMR separated by at least 28 days [1]. Individuals who have been previously vaccinated with two doses of MMR vaccine should receive a third dose of mumps virus-containing vaccine [49]. (See "Mumps", section on 'Outbreak settings'.)

●In a rubella outbreak setting, individuals who are incompletely immunized against rubella should receive two doses of MMR separated by at least 28 days [1].

Administration of immune globulin should not be used for outbreak control [3].

Post-exposure prophylaxis — Following measles exposure, post-exposure prophylaxis for susceptible individuals consists of MMR vaccination within 72 hours of exposure (in the absence of a contraindication) [1,50]. Administration of vaccine is preferable to administration of immune globulin since vaccination provides active, long-lasting immunity against measles [51].

Immune globulin can prevent or diminish the severity of measles if administered to nonimmune individuals within six days of exposure [3,52]. Immune globulin is not indicated for individuals who have received one dose of measles-containing vaccine at age ≥12 months in the absence of immunosuppression. Administration of immune globulin is appropriate for exposed individuals with increased risk of measles complications with contraindication for MMR vaccination as follows [1]:

●Pregnant women without evidence of immunity – Pregnant women may be at increased risk for severe measles and complications. Therefore, administration of intravenous immune globulin (IVIG; 400 mg/kg) is appropriate for pregnant women without evidence of measles immunity who have been exposed to measles.

●Immunocompromised patients – Severely immunocompromised patients exposed to measles should receive post-exposure prophylaxis with IVIG (400 mg/kg) regardless of immunologic or vaccination status. Such patients include individuals with severe immunodeficiency, bone marrow transplant recipients until at least 12 months after completing all immunosuppressive treatment (or longer in patients with graft-versus-host disease), patients on treatment for acute lymphoblastic leukemia until at least six months after completion of immunosuppressive chemotherapy, patients with HIV infection and CD4 percentage <15 percent (all ages) or CD4 count <200 cells/mm³ (age >5 years), and patients who have not received MMR vaccine since receiving effective antiretroviral therapy.

●Recommendations for use of IVIG in children, including infants, exposed to measles are discussed elsewhere. (See "Measles, mumps, and rubella immunization in infants, children, and adolescents", section on 'Measles postexposure prophylaxis'.)

Nonimmune individuals with measles exposure who received immune globulin should subsequently receive MMR vaccine (no earlier than six months after intramuscular immune globulin or eight months after IVIG), provided MMR vaccine is not otherwise contraindicated. (See 'Precautions' below.)

Following mumps or rubella exposure, neither post-exposure MMR nor immune globulin has been shown to prevent disease or lessen disease severity in the absence of an outbreak [1]. (See 'Outbreak settings' above.)

International travel — Before international travel, individuals who are incompletely immunized against measles should receive two doses of MMR separated by at least 28 days, with the first dose administered on or after the first birthday. Recommendations for children, including infants, are discussed elsewhere. (See "Immunizations for travel", section on 'Measles, mumps, and rubella' and "Measles, mumps, and rubella immunization in infants, children, and adolescents", section on 'International travel and outbreaks'.)

Other countries — Routine immunization schedules vary among countries. Schedules for individual countries are available through the World Health Organization.

CONTRAINDICATIONS — MMR and MMRV vaccines should NOT be administered to individuals who have certain conditions (table 2) [1,42]:

●Severe allergic reaction (eg, anaphylaxis) after a previous dose of MMR or to a vaccine component (eg, neomycin, gelatin). (See "Allergic reactions to vaccines".)

●Pregnancy or attempting to become pregnant – Women should be counseled to avoid becoming pregnant for 28 days after receiving MMR because of the theoretic risk of congenital rubella syndrome [1]. Pregnant women without immunity to measles, mumps, and rubella should receive a dose of MMR postpartum. (See "Rubella in pregnancy" and "Immunizations during pregnancy", section on 'Measles, mumps, rubella'.)

●Immunodeficiency – Individuals with immunodeficiency are at risk for severe complications following immunization with live attenuated virus vaccines (eg, encephalitis, pneumonitis) [1,53-58]. Immune deficiencies that are contraindications to MMR include:

•Primary or acquired immunodeficiency (eg, cellular immunodeficiency, hypogammaglobulinemia, HIV infection with CD4+ T lymphocyte [CD4] <200 cells/microL or percentage <15 percent). (See "Immunizations in persons with HIV", section on 'Measles, mumps, and rubella vaccine'.)

•Hematologic or solid tumor malignancy. (See "Immunizations in adults with cancer" and "Immunizations in solid organ transplant candidates and recipients" and "Immunizations in hematopoietic cell transplant candidates and recipients".)

•Long-term immunosuppressive therapy, including chemotherapy for malignancy, immunosuppression for transplant recipients, or large daily doses of corticosteroids (equivalent to ≥20 mg per day of prednisone) for ≥2 weeks [59]; MMR should be avoided for at least one month after high-dose corticosteroid therapy.

•History of congenital or hereditary immunodeficiency in a parent or sibling, unless the immune competence of the potential vaccine recipient has been substantiated clinically or verified by a laboratory.

Close contacts of patients with contraindications to MMR should receive routine vaccination; secondary transmission associated with MMR vaccination has not been reported [60].

PRECAUTIONS — When a precaution is present, the decision regarding vaccination should depend upon whether the benefit of protection from the vaccine outweighs the risk of an adverse reaction.

●Concurrent illness – Whether measles, mumps, and rubella (MMR) should be administered to individuals with current illness depends upon the severity of the illness. MMR can be safely administered to individuals with mild illness, with or without fever (eg, upper respiratory infection, otitis media, gastroenteritis); seroconversion is not affected by mild illness [61-63]. It is appropriate to delay administration of MMR in the setting of moderate to severe illness, unless the vaccine is being administered for measles exposure. (See 'Post-exposure prophylaxis' above.)

●Recent receipt of blood or immune globulin – Receipt of immune globulin or antibody-containing blood products can blunt or block the host response to certain live virus vaccines. The suggested interval between receipt of immune globulin or antibody-containing blood products and administration of MMR varies depending upon the product (table 3) [46,59,64].

Postpartum administration of MMR to women who received anti-D (Rho) immune globulin or blood products during the last trimester of pregnancy or at delivery is discussed separately. (See "Immunizations during pregnancy", section on 'Postpartum immunization'.)

●History of thrombocytopenia – Individuals with a history of thrombocytopenia or thrombocytopenic purpura may have an increased risk of clinically significant thrombocytopenia following immunization with MMR [1]. Decisions regarding administration of the first dose MMR to individuals with a history of thrombocytopenia are made on a case-by-case basis contingent upon the assessment of risks and benefits. In many cases, the benefits outweigh the risks.

Factors to be considered in the decision include:

•Recurrence of thrombocytopenia following MMR in individuals with a history thrombocytopenia (both vaccine-associated and nonvaccine-associated) has been reported [65-68], but the magnitude of the risk is unknown.

•The likelihood of exposure to MMR (eg, plans for international travel, level of MMR vaccination coverage in the community, etc).

Serologic testing can be performed to determine whether the second dose of MMR is necessary. Individuals with protective levels of antibody to MMR do not need to receive the second dose. For individuals with history of thrombocytopenia who lack protective levels of antibody to MMR, decisions regarding administration of the second dose of MMR are made on a case-by-case basis based upon the assessment of risks and benefits.

●Tuberculosis testing – MMR may temporarily reduce tuberculin skin test (TST) sensitivity [69]. The effect of MMR vaccination on interferon-gamma release assay (IGRA) is uncertain [1].

If TST or IGRA is warranted for evaluation of tuberculosis, they should be performed before, at the same visit as, or four to six weeks after MMR vaccination [1]. (See "Diagnosis of pulmonary tuberculosis in adults" and "Tuberculosis infection (latent tuberculosis) in adults: Approach to diagnosis (screening)".)

●History of seizure – Individuals with a personal or family history of seizures have an increased risk of febrile seizures following MMR, although this does not outweigh the benefits of immunization with MMR or MMRV [70,71]; the risk of seizures in children was estimated at one additional seizure per 2300 doses of MMRV versus MMR [72]. It is not known whether adults with a personal or family history of seizures have a similar risk. (See 'Adverse effects' below.)

●Concurrent use of antivirals – MMR vaccine can be administered to patients on antivirals. However, for patients receiving MMRV vaccine, antiviral drugs with activity against herpes viruses (eg, acyclovir, valacyclovir) may interfere with the varicella component of the vaccine; for these patients, the antiviral should be discontinued ≥24 hours before administration of the MMRV vaccine and avoided for 14 days after vaccination.

ADVERSE EFFECTS — Adverse reactions to measles, mumps, and rubella (MMR) include fever, rash, lymphadenopathy, joint complaints, hypersensitivity reactions, development of immune thrombocytopenia (ITP), and seizures. These reactions occur more frequently with the first than with the second dose [73].

●Fever – Fever (>39.4ºC) develops in 5 to 15 percent of MMR recipients, usually within 6 to 12 days after immunization [46].

●Rash – Transient rashes also occur in approximately 5 percent of MMR recipients [46]. The combination of fever and rash after MMR immunization generally is attributed to measles vaccine virus but may be due to wild-type measles or other viral illnesses [74]; virologic studies may be warranted in individuals with potential exposure to wild-type measles (eg, international travel, contact with immigrants).

●Lymphadenopathy – Transient lymphadenopathy occurs in 5 percent of children and 20 percent of adults [1].

●Joint manifestations – Joint manifestations secondary to the rubella component of the vaccine may occur 7 to 21 days after MMR immunization [46]. Arthralgia occurs in 25 percent of adults, and 10 percent develop arthritis [3].

●Hypersensitivity reaction – Hypersensitivity reactions to the MMR are usually minor (wheal and flare or urticaria) and have been attributed to trace amounts of neomycin or gelatin but not to egg antigens since MMR does not contain significant amounts of egg-white cross-reacting proteins [46,75,76]. (See "Allergic reactions to vaccines".)

●Thrombocytopenia – Thrombocytopenia has been observed in prospective studies (1 case in 25,000 to 40,000 vaccine doses) [3]. In general, it is transient and occurs within two months of the receipt of vaccine, most commonly at two to three weeks. The risk may be higher in individuals who experienced thrombocytopenia following previous vaccination with MMR. (See 'Precautions' above and "Measles, mumps, and rubella immunization in infants, children, and adolescents", section on 'Adverse effects'.)

●Febrile seizure – The incidence of vaccine-associated seizures has been estimated to be 1 in 3000 MMR doses [3] but is increased in individuals with a history of seizures or with a family history in first-degree relatives. Most are simple febrile seizures and in most cases the benefits of vaccination outweigh the risk of seizures. As noted above, in children there was an estimated one additional febrile seizure in one of every 2300 doses of MMRV versus MMR [72]. (See 'Precautions' above and "Measles, mumps, and rubella immunization in infants, children, and adolescents", section on 'Adverse effects'.)

●MMR does not appear to be associated with encephalopathy. In a retrospective case-control study including 452 children with encephalopathy and related conditions and up to three controls for each case, cases were no more likely than controls to have received MMR during the 90 days before onset of encephalopathy [77].

ADMINISTRATION — Measles, mumps, and rubella (MMR) combination vaccine are supplied as a lyophilized (freeze-dried) powder with a separate diluent. Only the diluent that is supplied with the vaccine should be used to reconstitute it; any dose of vaccine that is reconstituted with the incorrect diluent should be repeated.

The dose of MMR is 0.5 mL [59]. All formulations of MMR can be administered subcutaneously with a 5/8 inch (1.6 cm), 23-to 25-gauge needle [78,79]. The site of subcutaneous administration of individuals >12 months of age is usually the upper outer triceps. Immunogenicity appears to be similar with intramuscular and subcutaneous administration, and some formulations have also been approved for administration via the intramuscular route; refer to local product information for guidance [78-80]. If a formulation intended for subcutaneous use is administered intramuscularly, the dose need not be repeated.

MMR may be administered at the same clinic visit as other immunizations [81]. However, if live attenuated vaccines (eg, MMR, varicella, live attenuated influenza, yellow fever) are not administered at the same clinic visit, they should be separated by ≥28 days [59]. Administration at <28 days may impair the immune response to one of the vaccines [82-84].

SPECIAL POPULATIONS

HIV infection — As stated above, MMR vaccination is contraindicated for individuals with HIV infection and severe immunocompromise (CD4+ T lymphocyte [CD4] percentage <15 percent or CD4 count <200 cells/microL). (See 'Contraindications' above.)

MMR vaccination is warranted for individuals with HIV infection in the absence of severe immunocompromise and no evidence of immunity for measles, mumps, and rubella; such individuals should be immunized with two doses of MMR vaccine, given at least 28 days apart [1,53]. (See 'Documenting immunity' above and "Immunizations in persons with HIV", section on 'Measles, mumps, and rubella vaccine'.)

Contact with immunocompromised hosts — MMR can be given to individuals with immunocompromised household contacts, who are at increased risk for severe complications from natural measles infection [53,59]. A 2007 review found no evidence of secondary transmission of measles, mumps, or rubella vaccine viruses from healthy vaccinees caring for or living with immunocompromised contacts [60].

History of measles, mumps, or rubella infection — Individuals with clinical history of measles, mumps, or rubella infection that was not laboratory confirmed should be vaccinated as if they have not had infection [1]. Individuals with laboratory confirmation of measles, mumps, or rubella disease are considered to be immune to that particular disease and need not be vaccinated against it. However, individuals generally receive two doses of MMR vaccine regardless because monovalent vaccines for measles, mumps, or rubella are no longer available in the United States.

Egg allergy — Egg allergy is not a contraindication or precaution to MMR; vaccination can be administered to individuals with egg allergy without prior skin testing or special protocols [1]. (See "Allergic reactions to vaccines", section on 'Measles, mumps, and rubella'.)

Immigrants and refugees — Issues related to immigrants and refugees are discussed separately. (See "Medical care of adult refugees, immigrants, and migrants", section on 'Immunizations'.)

LACK OF ASSOCIATION WITH AUTISM — Multiple studies have failed to demonstrate any association between measles, mumps, and rubella (MMR) vaccination and autism or other chronic diseases. However, there is an association between congenital rubella syndrome and autism, highlighting a potential role for MMR immunization in the prevention of autism spectrum disorders [85]. (See "Autism spectrum disorder and chronic disease: No evidence for vaccines or thimerosal as a contributing factor".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Immunizations in adults".)

SUMMARY AND RECOMMENDATIONS

●General recommendations for MMR vaccine in adults – We recommend that adults born in 1957 or later (who are not included in the categories summarized above) should have documentation of at least one dose of measles, mumps, and rubella (MMR) vaccine unless there is laboratory evidence of immunity to each of the three diseases or a medical contraindication to vaccination (Grade 1A). (See 'Who should be immunized' above.)

●Documenting immunity – For adults in the categories summarized above, formal documentation of immunity to measles, mumps, and rubella diseases should be established; in the absence of evidence for immunity, we recommend that two doses of the MMR vaccine should be administered at least 28 days apart (Grade 1A). (See 'Who should be immunized' above and 'Documenting immunity' above.)

●Definition of immunity – Evidence of immunity is established by the following (see 'Documenting immunity' above):

•Documentation of age-appropriate vaccination with a live attenuated vaccine (vaccination reported by a caregiver is not valid without appropriate documentation):

-For measles – Two doses of measles-containing vaccine, both administered at ≥12 months of age, separated by ≥28 days (doses administered before 12 months of age are not counted)

-For mumps – Two doses of mumps-containing vaccine, both administered at ≥12 months of age, separated by ≥28 days (doses administered before 12 months of age are not counted)

-For rubella – One dose of rubella-containing vaccine administered at ≥12 months of age, except for pregnant women who require laboratory evidence of immunity or confirmation of disease

•Laboratory evidence of immunity (measles, mumps, and rubella immunoglobulin [Ig]G).

•Laboratory confirmation of measles, mumps, and rubella disease (clinical diagnosis without laboratory confirmation is not sufficient evidence of immunity)

•Birth before 1957 – Individuals born before 1957 are generally considered immune to measles and mumps (except health care workers). Rubella immunity should be determined by laboratory testing for all women of childbearing age regardless of birth year. (See 'Who should be immunized' above.)

●Medical management of exposures – Post-exposure prophylaxis for susceptible individuals exposed to measles consists of MMR vaccination within 72 hours of exposure (in the absence of a contraindication). If more than 72 hours but less than 6 days have elapsed since exposure, intramuscular immune globulin may prevent or modify measles infection in nonimmune individuals with increased risk of measles complications (including pregnant women without evidence of immunity and immunocompromised patients).

Following mumps or rubella exposure, neither post-exposure MMR nor immune globulin has been shown to prevent disease or lessen disease severity. (See 'Post-exposure prophylaxis' above.)

●Contraindications – Contraindications to MMR vaccine include severe allergic reaction after a previous dose or to a vaccine component (eg, gelatin, neomycin), pregnancy, and immunodeficiency (table 2). (See 'Contraindications' above.)

●Indications for altered schedule of vaccination – Circumstances that may affect the timing of MMR immunization include receipt of blood products or immune globulin within the past 11 months, history of thrombocytopenia or thrombocytopenic purpura, need for tuberculosis testing, concurrent illness, and HIV infection (table 2). (See 'Special populations' above.)