Measles, mumps and rubella

• Measles, mumps and rubella are three different RNA viruses that spread by respiratory droplets and aerosols and are preventable by one combined live vaccine, MMR.
• Measles is the most contagious of the three and causes a prodrome of fever, cough, coryza and conjunctivitis followed by a descending maculopapular rash, with potentially severe complications including pneumonia and encephalitis.
• Mumps classically causes parotid swelling and can inflame the testes, ovaries, pancreas, nervous system and inner ear.
• Rubella is usually a mild rash illness in children, but infection in early pregnancy can cause congenital rubella syndrome with deafness, eye defects and congenital heart disease.
• Prevention is the same strategy for all three: two doses of MMR vaccine in childhood, with a third dose of MMR sometimes used for mumps outbreaks.

By the end of this page you should be able to:

1. Recognise measles, mumps and rubella clinically and distinguish them from common mimics.
2. Explain the complications of each infection and who is most at risk.
3. Outline how a measles, mumps or rubella case is confirmed in the laboratory.
4. Describe vaccination schedules, contraindications and efficacy for MMR and MMRV vaccines.
5. Explain congenital rubella syndrome and why rubella vaccination in women of childbearing age matters.
6. Plan the public-health response to a suspected case or outbreak, including isolation and post-exposure prophylaxis.

Each virus is a systemic infection that begins in the respiratory tract and spreads through the bloodstream (viraemia). Measles and mumps are paramyxoviruses; rubella is not, despite the similar name "German measles". The diseases are clinically distinct even though rubella and measles both produce a maculopapular rash, and mumps and measles both spread in the same respiratory way. ^[8]

Measles remains one of the leading vaccine-preventable causes of death in young children. The World Health Organization (WHO) estimates that measles caused about 95,000 deaths globally in 2024, mostly in unvaccinated or under-vaccinated children under 5 years of age, and that measles vaccination averted nearly 59 million deaths between 2000 and 2024. ^[6] In 2025 about 84% of children worldwide received a first dose of measles vaccine by their first birthday and 77% received two doses; roughly 29 million infants remained under-protected. ^[6]

Rubella is milder but is the leading vaccine-preventable cause of birth defects. WHO estimates about 100,000 infants are born with congenital rubella syndrome (CRS) each year worldwide, and that in 2022 there were an estimated 17,865 rubella cases in 78 countries. ^[7] As of January 2025, 179 of 194 countries had introduced rubella-containing vaccines, with global coverage estimated at 73%. ^[7] Reported rubella cases fell 97% from 670,894 cases in 102 countries in 2000 to 17,865 in 78 countries in 2022. ^[7]

Mumps occurs worldwide, with about 500,000 cases reported on average each year, and has no seasonal pattern. ^[2]

Before the vaccines, measles caused epidemics every 2 to 3 years. In the decade before the live vaccine was licensed in 1963, an average of about 549,000 measles cases and 495 measles deaths were reported annually in the United States, although 3 to 4 million people were probably infected each year. ^[4] Measles was declared eliminated in the United States in 2000, but cases and outbreaks still occur, mostly imported and mostly in unvaccinated people. ^[1][4]

Mumps was one of the most common causes of aseptic meningitis and hearing loss in children before vaccination. About 152,000 mumps cases were reported when the disease became nationally notifiable in 1968, falling to fewer than 300 by 2004 after two-dose vaccination began. ^[2] Since 2006, outbreaks have recurred, mostly in fully vaccinated people in close-contact settings such as colleges and sports teams. ^[2]

Rubella became notifiable in 1966. After vaccine introduction in 1969, reported rubella cases declined 78% from 57,686 in 1969 to 12,491 in 1976, and reported CRS cases declined from 68 in 1970 to 23 in 1976. Endemic rubella was declared eliminated in the United States in 2004, with fewer than 10 rubella cases and less than one CRS case per year. ^[3][8] In 2004 the Americas became the first WHO region declared free of endemic rubella transmission. ^[3]

Measles is one of the most contagious infections known: up to 9 out of 10 susceptible people with close contact to a case develop measles, and the virus stays infectious in the air for up to 2 hours after a case leaves a room. ^[4] A single measles case can generate up to 18 secondary infections. ^[6] Mumps is about as transmissible as influenza or rubella but less so than measles or chickenpox. ^[2] Measles spreads person-to-person via large respiratory droplets and aerosolised droplet nuclei. ^[1] Mumps spreads in saliva and infectious respiratory droplets. ^[2] Rubella spreads by direct contact or respiratory droplets and has no known animal reservoir or insect vector. ^[3][7]

• Measles is contagious from 4 days before through 4 days after rash onset. ^[1][4][6]
• Mumps is contagious from 2 days before through 5 days after parotid swelling begins. ^[2]
• Rubella is contagious from 7 days before to 7 days after rash onset; infants with CRS may shed virus for up to 1 year. ^[3][7]

No modifiable risk factor exists for catching these viruses beyond not being vaccinated. Risk is determined by susceptibility: lack of immunity, young age, malnutrition, pregnancy, or immunosuppression.

• Measles: complications are most common in children under 5 years and adults over 30, and more likely in children who are malnourished, especially without enough vitamin A, or with weakened immunity from HIV or other causes. ^[6] Measles itself weakens immune memory ("immune amnesia"), leaving children prone to other infections for months to years. ^[4]
• Mumps: complications are more common in adults than in children. ^[2] Humans are the only reservoir; no animal or insect reservoir and no carrier state is known. ^[2]
• Rubella: the risk of CRS is highest in countries where women of childbearing age lack immunity. ^[7] Before vaccination, up to 4 babies per 1,000 live births were born with CRS. ^[7]

Other risk factors worth noting: measles is imported by travellers and outbreaks follow under-immunised groups. In the United States, recent outbreaks cluster in close-knit under-vaccinated communities. ^[1]

The measles virus targets the F (fusion) protein, which fuses viral and host membranes, and the H (haemagglutinin) protein, which binds to host receptors. ^[1] The primary site of infection is alveolar macrophages or dendritic cells. The virus replicates in the lung, spreads to regional lymphoid tissue, then causes a systemic viraemia. A second viraemia around 5 to 7 days after infection seeds the respiratory epithelium, from which the virus is released. ^[1] There is only one antigenic type, and studies showing changes in the H protein have not changed vaccine efficacy. ^[1]

The virus is acquired by respiratory droplets, replicates in the nasopharynx and regional lymph nodes, then spreads in the blood to the meninges, salivary glands, pancreas, testes and ovaries. Inflammation in infected tissues produces parotitis, orchitis and the other complications. ^[2]

After respiratory transmission, rubella virus replicates in the nasopharynx and regional lymph nodes. In a pregnant woman, placental infection occurs during viraemia and may lead to transplacental fetal infection. Fetal damage happens both by destruction of cells and by disruption of cell division, and the infection usually persists, leading to hearing impairment and ocular and cardiovascular abnormalities. ^[3] A distinctive feature of measles is that natural infection gives long-term immunity. Rubella vaccine gives immunity similar to natural infection. ^[7]

Incubation: the period from exposure to prodrome averages 11 to 12 days; exposure to rash onset averages 14 days, with a range of 7 to 21 days. ^[1]

Prodrome (2 to 4 days, range 1 to 7 days): stepwise rise in fever to 103°F to 105°F (about 39.4°C to 40.6°C), cough, coryza (runny nose) and conjunctivitis. This trio is the classic "3 Cs". ^[1][4] Anorexia and generalised lymphadenopathy may occur. ^[1]

Koplik spots: considered unique to measles. They are punctate blue-white spots on a bright red background of the buccal mucosa, appearing 1 to 2 days before the rash, during the prodrome. ^[1][4]

Rash: maculopapular, lasting 5 to 6 days. It begins at the hairline, then the face and upper neck, and spreads downwards and outwards to the hands and feet over about 3 days. Early lesions blanch with pressure; by day 3 to 4 most do not. Lesions may merge on the upper body. The rash then fades in the same order it appeared, with scaling in more severely affected areas. ^[1][4] Measles is usually clinically apparent, although immunocompromised patients may not develop a rash and may shed virus for several weeks. ^[8]

Incubation: usually 16 to 18 days, range 12 to 25 days. ^[2] A nonspecific prodrome of myalgia, anorexia, malaise, headache and low-grade fever precedes parotitis. ^[2] Parotid swelling lasts about 5 days and may be unilateral or bilateral, sometimes appearing on the other side weeks to months later. ^[2] Parotitis may first present as earache and tenderness on palpating the angle of the jaw. ^[2] Mumps is the only infectious agent known to cause epidemic parotitis. ^[2] Before vaccination, 15% to 24% of infections were asymptomatic; infection is generally milder in vaccinated people and may present with only respiratory symptoms or be subclinical. ^[2]

Incubation: average 14 days, range 12 to 23 days. ^[3] In young children the rash is often the first symptom. Older children and adults may have a 1 to 5 day prodrome of low-grade fever, malaise, lymphadenopathy and upper respiratory symptoms. ^[3] Forchheimer spots (small red spots on the soft palate) may be seen. ^[3]

The rubella rash is maculopapular, occurring 14 to 17 days after exposure, starting on the face and progressing down the body, lasting about 3 days. It is fainter than measles, does not coalesce, and is often more noticeable after a hot shower or bath. ^[3] Post-auricular, posterior cervical and sub-occipital lymph nodes may be enlarged and can begin a week before the rash. ^[3] Joint pains (arthralgia, arthritis) are rare in children and adult men but common in adult women, usually starting with or just after the rash and lasting up to 1 month, affecting fingers, wrists and knees; chronic arthritis is rare. ^[3] Up to 50% of rubella infections are subclinical or inapparent. ^[3][8] WHO describes rubella as a mild disease in children with rash, low fever (under 39°C), nausea and mild conjunctivitis, with swollen lymph glands behind the ears and neck as the most characteristic feature. ^[7]

• Measles: look for the "3 Cs" plus Koplik spots on the buccal mucosa. The rash spreads downward and outward; severe areas may scale. ^[1]
• Mumps: swelling of the parotid gland, which lifts the earlobe and obscures the angle of the jaw. Check the testes in post-pubertal males for orchitis. ^[2]
• Rubella: faint maculopapular rash, post-auricular and occipital lymphadenopathy, and (in adult women) swollen joints. ^[3]

A useful vignette: a student with high fever, cough, coryza, conjunctivitis and white spots on the inner cheek two days before a red rash that started at the hairline and spread downward, in a setting with low vaccination coverage. This is measles until proven otherwise. ^[1]

Table 1 compares the skin and salivary presentations.

Measles mimics: other morbilliform (measles-like) rashes such as drug eruptions, enterovirus infection, dengue or Kawasaki disease. Koplik spots and the descending rash plus the "3 Cs" make measles likely; confirm with IgM and RT-PCR. ^[1][4]

Mumps mimics: other viral parotitis (enteroviruses, Epstein-Barr virus, cytomegalovirus, influenza A including H3N2, parainfluenza types 1 and 3, HIV, lymphocytic choriomeningitis virus, non-tuberculous mycobacteria) must be considered; mumps is the only cause of epidemic parotitis. ^[2]

Rubella mimics: many rash illnesses look like rubella, so clinical diagnosis is unreliable and laboratory confirmation is needed. ^[3]

Other differential considerations: rubella-related arthritis in adult women can mimic rheumatoid arthritis; mumps orchitis can mimic testicular torsion or bacterial epididymo-orchitis; measles croup and bronchopneumonia can be mistaken for other viral respiratory infections.

Measles is a mandatory, immediately notifiable disease. Collect a throat or nasopharyngeal swab for reverse-transcriptase polymerase chain reaction (RT-PCR) and a serum specimen for measles-specific IgM from every suspected case at first contact, plus a urine sample when feasible. ^[4] RT-PCR detects measles RNA and IgM serology detects the immune response; viral genotyping by public health laboratories tracks transmission pathways and distinguishes wild-type infection from recent vaccine virus. ^[1][4]

Confirmation is by RT-PCR or viral culture from buccal or oral swabs or urine; IgM may be transient, delayed or absent, especially after vaccination, so a negative IgM or RT-PCR does not rule out mumps in a compatible case. ^[2] Collect serum 3 to 10 days after parotitis onset to improve IgM detection; paired acute and convalescent sera showing a significant IgG rise are another option, but acute-phase IgG may already be high in previously vaccinated people. ^[2]

Laboratory confirmation is needed because clinical diagnosis is unreliable. Options are detection of rubella virus by PCR, a significant rise in rubella IgG from paired acute and convalescent sera, or rubella-specific IgM. The best time to collect serum for IgM is 5 days after onset of symptoms (fever and rash); if collected earlier and negative, repeat. ^[3] Rubella virus can be found in nasal, throat, urine, blood and cerebrospinal fluid up to 10 days after rash onset (most successfully within 3 days). ^[3]

In an infant with suspected CRS, collect nasopharyngeal swabs and/or urine as close to birth as possible. If CRS is confirmed, screen monthly after 3 months of age until two consecutive negative tests; viral shedding can last up to 1 year. ^[3]

• Erythrocyte sedimentation rate and C-reactive protein may be raised in measles, but no blood test diagnoses it; blood cultures help if bacterial superinfection is possible. ^[1]
• In measles pneumonia, chest imaging and oxygen assessment guide supportive care.
• Serology for immunity (IgG) is used to check immune status in women of childbearing age for rubella. ^[3]

There is no staging system for these illnesses in the ordinary sense; diagnostic confidence rests on a compatible clinical picture plus laboratory confirmation. A few framed thresholds are useful:

• Measles clinical case definition: fever with maculopapular rash plus cough, coryza or conjunctivitis. Laboratory confirmation is essential for all sporadic cases and outbreaks. ^[4][5]
• SSPE risk: a late, usually fatal neurological complication developing after measles, with risk of 4 to 11 per 100,000 measles cases, higher when measles occurs in children under 2 years. ^[4][8]
• Congenital rubella syndrome is diagnosed from the combination of compatible findings (deafness, eye abnormalities such as cataracts, glaucoma, retinopathy or microphthalmia, congenital heart disease) plus laboratory evidence. Prevention, not treatment, is the main goal. ^[3][7]
• Mumps vaccine effectiveness: a single dose is about 78% effective and two doses about 88% effective against disease, and roughly 94% of recipients develop measurable antibody. ^[2]

None of measles, mumps or rubella has a specific antiviral treatment. Care is supportive: hydration, antipyretics, rest, treatment of bacterial superinfections. ^[4] The cornerstone of preventing spread is isolation and early notification, because measles in particular is transmissible before the rash appears. ^[1][4]

Measles. There is no FDA-approved antiviral for measles; medical care is supportive. ^[4] Antibiotics are not used routinely but are indicated for secondary bacterial infection such as pneumonia or otitis media. ^[4] Ribavirin has been used in severely immunocompromised patients or severe disease such as encephalitis or pneumonia, but it is not FDA-approved for measles and clinical efficacy data are lacking. ^[4]

Vitamin A is recommended by WHO for all suspected measles cases in children under 5: two doses, immediately on diagnosis and repeated the next day; a third dose 4 to 6 weeks later is recommended if there are clinical signs of vitamin A deficiency with eye complications. Age-based doses used in the United States are 50,000 IU for infants under 6 months, 100,000 IU for infants 6 to 11 months, and 200,000 IU for children 12 months and older. ^[4][6] Vitamin A does not prevent measles and is not a substitute for vaccination. ^[4]

Congenital measles in a newborn (febrile rash within 10 days of birth) is serious and may cause encephalitis and death, with higher SSPE risk. Providing immune globulin to the neonate may prevent or attenuate congenital measles. ^[4]

Mumps. Supportive care; analgesia for parotitis and orchitis, scrotal support, hydration. No antiviral is available. ^[2] Suspected mumps is confirmed by laboratory testing and reported locally. ^[2]

Rubella. Supportive care only. Arthralgia in adult women may need analgesia. ^[3]

• Measles: isolate for 4 days after rash onset; airborne precautions in healthcare settings, preferably in a single-patient airborne infection isolation room, with N95 or equivalent respirators for staff regardless of presumed immunity. ^[4][8]
• Mumps: most transmissible around parotitis onset; standard droplet precautions are used and patients are kept home for 5 days after swelling begins. ^[2]
• Rubella: patients are contagious from 7 days before to 7 days after rash onset; isolate away from pregnant and non-immune contacts, especially women of childbearing age. ^[3][7]

Prompt recognition, reporting and investigation limit spread. ^[5]

• Case finding and notification: measles and rubella are nationally notifiable; report suspected cases to the local health department promptly. ^[4][5]
• Quarantine of susceptible contacts: contacts without presumptive evidence of immunity may be quarantined. ^[5]
• Post-exposure prophylaxis for measles: if given within 72 hours (3 days) of exposure, MMR vaccine may provide some protection or modify disease in limited-contact settings such as schools, childcare and medical offices; it is not effective in settings of intense, prolonged close contact such as households, even within 72 hours. ^[8] Immune globulin is used for infants (including, in the 2013 revision, infants from birth to 6 months exposed to measles), immunocompetent contacts at increased dose, and intravenous immune globulin for severely immunocompromised people and pregnant women without immunity who are exposed to measles. ^[8]
• Mumps outbreaks: during an outbreak, a third dose of MMR is recommended for groups public health authorities identify as at increased risk, including people without records of two doses and those with presumptive immunity; no extra dose is recommended for those who already had three or more. ^[2]
• Rubella outbreaks: control and prevent CRS by vaccinating susceptible post-pubertal women, adolescents and other at-risk groups, and by preventing infection in pregnant women. ^[3][8]

Refer any person with suspected measles, mumps or rubella in pregnancy, or with suspected CRS, complications (encephalitis, pneumonia, myocarditis), or inability to maintain hydration, to hospital and to public health. Suspected cases should be discussed with the infectious disease or public health team, because decisions about isolation, prophylaxis and pregnancy management are time-critical. ^[4][5]

• Measles: watch for pneumonia, otitis media and encephalitis during and after illness; SSPE may appear years later. ^[4][8]
• Mumps: monitor for orchitis and hearing loss; arrange audiometry if hearing symptoms occur. ^[2]
• Rubella: ensure immunity in women of childbearing age; test infants with CRS for ongoing viral shedding. ^[3]

Complications are most common in children under 5 years and adults, and about 30% of measles cases in the United States between 1987 and 2000 had one or more complication. ^[1][6] Documented complications include diarrhoea, otitis media, pneumonia (including bronchopneumonia and croup), encephalitis, subacute sclerosing panencephalitis (SSPE) and death. ^[1][4] From 1987 to 2000 the most commonly reported complications were pneumonia (6%), otitis media (7%) and diarrhoea (8%). ^[8]

Acute encephalitis occurs in about 1 in 1,000 cases and often leaves permanent brain damage. ^[4][8] About 1 to 3 in every 1,000 children infected die from respiratory or neurological complications. ^[4] SSPE is a rare, fatal degenerative brain disease with onset on average 7 to 10 years after infection; risk is 4 to 11 per 100,000 measles cases, higher when infection occurs before age 2. ^[4][8] Measles case-fatality can be as high as 25% in malnourished populations in low- and middle-income countries. ^[8] High fever and severe malnutrition, especially vitamin A deficiency, increase risk. ^[6]

Congenital (intrauterine) measles can occur and presents as a febrile rash syndrome within 10 days of birth, with high risk of severe complications, encephalitis and death, and higher SSPE risk. ^[4]

Complications include orchitis, oophoritis, mastitis, pancreatitis, sensorineural hearing loss, meningitis and encephalitis, and are usually more common in adults than children. ^[2]

• Orchitis is the commonest complication in post-pubertal males: about 30% of unvaccinated and 6% of vaccinated. Pain, testicular swelling and fever occur; about half develop testicular atrophy, but sterility has not been demonstrated to result. ^[2]
• Oophoritis and mastitis occurred in about 7% and 30% of post-pubertal women in the pre-vaccine era; in vaccinated women 1% or fewer. ^[2]
• Aseptic meningitis occurred in up to 10%, pancreatitis up to 4%, and sensorineural hearing loss up to 4% of unvaccinated patients. ^[2][8]
• In the post-vaccine era, meningitis, encephalitis, pancreatitis and hearing loss have each been 1% or less among all infected people. ^[2]
• Nephritis, myocarditis, paralysis, seizures, cranial nerve palsies and hydrocephalus are reported but rare. ^[2]
• Permanent sequelae and death are very rare in both vaccinated and unvaccinated patients. ^[2]

Mumps in the first trimester is associated with increased spontaneous abortion or fetal death, but not birth defects. ^[8]

Complications are rare. Haemorrhagic manifestations, mainly thrombocytopenic purpura, occur in about 1 in 3,000 cases; encephalitis in about 1 in 6,000; granulomas (more common in primary immune deficiency), orchitis, neuritis and progressive panencephalitis are reported. ^[3][8] Joint symptoms are common in adult women. ^[3]

Congenital rubella syndrome (CRS) is the most consequential outcome of rubella and the main target of vaccination programmes. ^[3][7] Infection in early pregnancy, especially the first 12 weeks of gestation, carries the highest risk of miscarriage, fetal death, stillbirth and birth defects; defects are rare after 20 weeks. ^[3][7][8] On passing the virus to the fetus early in pregnancy, a woman has about a 90% chance of fetal infection. ^[7]

Classical CRS findings include:

• deafness,
• eye abnormalities (cataracts, glaucoma, retinopathy, microphthalmia),
• congenital heart disease,
• intrauterine and postnatal growth retardation,
• hepatosplenomegaly, thrombocytopenia, "blueberry muffin" rash and other findings may be present. ^[3][7]

Congenital infection without clinical CRS signs can also occur at any gestational age. Reinfection in pregnancy is usually of minimal fetal risk unless it occurs in the first 12 weeks. ^[8] WHO estimates roughly 100,000 infants are born with CRS annually. ^[7] Infants with CRS may excrete rubella virus for a year or more, infecting susceptible carers. ^[3][7]

Table 2 summarises complications across the three diseases.

Measles has a case-fatality ratio that can be high (up to 25%) in malnourished populations in low- and middle-income countries, but under 1 per 1,000 in well-nourished settings. ^[4][8] Recovery usually confers lifelong immunity. ^[1] Mumps and rubella are usually mild in children; long-term damage (deafness in mumps, CRS in rubella) drives most of the burden. ^[2][3] Rubella infection is usually followed by long-lasting immunity similar to vaccination. ^[7]

MMR vaccine is the combined live attenuated vaccine for measles, mumps and rubella. ^[1][2][3] It is given subcutaneously. ^[1]

Routine schedule (United States): two doses of MMR, first at 12 to 15 months, second at 4 to 6 years, before school entry. Minimum age for dose 1 is 12 months, and the minimum interval between doses is 4 weeks for MMR and 3 months for MMRV (a 4-week interval is considered valid). ^[1][2][3] MMRV (measles, mumps, rubella, varicella) is licensed for 12 months to 12 years and should not be given to anyone older than 12; in children 12 to 47 months, febrile seizure risk is about twice as high with MMRV, so separate MMR and varicella is preferred for dose 1 unless the caregiver prefers MMRV. MMRV is generally preferred for dose 2 and for dose 1 from 48 months. ^[1][2][3]

A first dose at 6 to 11 months is given to infants travelling internationally or in high-risk settings; that dose does not count toward the two-dose series, and two appropriately spaced doses should be given after 12 months. ^[1][2][3]

Adults: adults born in 1957 or later should receive at least one dose unless they have documentation or other acceptable presumptive evidence of immunity. Those in high-risk groups need two doses for measles and mumps (college and post-high-school students, healthcare personnel, international travellers) and at least one dose for rubella; healthcare personnel born before 1957 who lack immunity should also be offered two doses for measles and mumps and one dose for rubella. ^[1][2][3][8] Birth before 1957 is generally considered acceptable evidence of immunity for measles and mumps, but for rubella it is not acceptable for women who could become pregnant. ^[1][2][3]

Efficacy: measles antibodies develop in about 95% of children vaccinated at 12 months and in over 99% of those receiving two doses. ^[1] Rubella immunity develops in at least 95% after one dose, with long-lasting (probably lifelong) protection. ^{[3] [7]} Mumps antibody develops in about 94% after one dose; effectiveness is about 78% after one dose and about 88% after two. ^[2]

Immunity as evidence: being born before 1957, serologic evidence (equivocal results treated as negative), laboratory-confirmed disease, or documentation of adequate vaccination. Note that mumps IgG antibody does not necessarily predict protection during an outbreak. ^[1][2][3]

Safety and contraindications: MMR is contraindicated in severe immunocompromise, pregnancy, and severe allergic reaction to a vaccine component or previous dose. It should not be given to people receiving systemic high-dose corticosteroids (2 mg/kg/day or more, or 20 mg or more of prednisone daily) for 14 days or more, until at least 1 month after stopping treatment, and should not be given within 3 to 11 months of immune globulin or other antibody-containing blood products. Severe immunocompromise from medications is judged case by case. HIV infection without severe immunosuppression is not a contraindication: MMR is recommended for people with HIV aged 12 months or older with adequate CD4 measures (CD4 percentage at least 15% for 6 months or more, and for those over 5 years CD4 count at least 200 cells/mm3). MMRV is not approved for people with HIV. If a pregnant woman is inadvertently vaccinated, termination of pregnancy is not recommended; counselling is provided. MMRV, not MMR, is the preparation precaution for simultaneous aspirin use, personal or family seizure history, and antiviral drugs around vaccination. MMR may be given to egg-allergic people. ^[1][2][3]

Adverse effects: after MMR, 5 to 15% of susceptible people develop fever of 103°F (39.4°C) or higher 7 to 12 days later, lasting 1 to 2 days; about 5% get a transient rash; febrile seizures occur in about 1 in 3,000 to 4,000 doses; anaphylaxis in 1.8 to 14.4 per million doses. Arthralgia occurs in up to 25% of adult women, attributed to the rubella component; parotitis after the mumps component is rare (under 1%). Thrombocytopenia can occur within 2 months. ^[1][2][3] With MMRV, fever of 102°F or higher occurs in about 21.5% of recipients aged 12 to 23 months and one additional febrile seizure per 2,300 to 2,600 children in that age group compared with separate MMR and varicella. ^[2][3]

Pregnancy and vaccination: MMR is contraindicated in pregnancy and pregnancy should be avoided for 4 weeks after vaccination. If a non-immune pregnant woman is exposed to rubella, counselling and fetal assessment are needed. ^[1][2][3][7] Data from 321 susceptible women vaccinated inadvertently showed no CRS in offspring; studies in six Latin American countries found no CRS-associated defects among 1,980 followed women (70, or 3.6%, of infants had congenital infection but no CRS defects). ^[3]

Table 3 compares vaccine schedules from country perspectives.

• Rubella immunity testing: all women of childbearing age should have documented rubella immunity; non-immune women should be vaccinated, avoiding pregnancy for 4 weeks. ^[3][7]
• Measles immunity: especially for healthcare staff and students entering college. ^[1][8]
• Outbreak-prone groups: third MMR dose for mumps outbreaks as advised by public health; extra measles dose for travellers. ^[1][2]

Children under 5 years: at highest risk of measles complications and most likely to need vitamin A; school entry usually requires two MMR doses. ^[1][6]

Pregnancy: measles in pregnancy can cause pneumonia, death, miscarriage, premature delivery and low birth weight but is not teratogenic. ^[4][8] Rubella in early pregnancy can cause CRS, the main reason to vaccinate women before conception. ^[3][7] Mumps in the first trimester may increase miscarriage but does not cause birth defects. ^[8] MMR is contraindicated in pregnancy. ^[1][2][3]

Immunocompromised people: live MMR is contraindicated in severe immunocompromise but is recommended in HIV without severe immunosuppression. People with HIV not previously immunised should be assessed and vaccinated where appropriate; revaccination after starting effective antiretroviral therapy may be needed. ^[1][2][3][8]

Older adults: people born before 1957 are generally considered immune to measles and mumps. Rubella immunity is less certain, particularly in women who could become pregnant. ^[1][2][3]

Refugees and displaced people: measles outbreaks are particularly dangerous in crowded settings; vaccination as soon as possible is advised. ^[6]

• The single most effective action is high two-dose MMR coverage through routine immunisation and catch-up campaigns. The vaccine costs less than one US dollar per child. ^[6][7]
• In settings with limited laboratory access, clinical diagnosis and notification must still trigger reporting and contact tracing. RT-PCR may be unavailable, so IgM serology is the practical confirmatory test; collect serum and ship properly. ^[1][3][4]
• Vitamin A distribution already used for other indications can be harnessed for measles cases. ^[4][6]
• Isolate cases, improve ventilation and keep measles wards separate; airborne transmission persists for up to 2 hours. ^[1][4]
• CRS can only be prevented by immunity in women before pregnancy; in countries with low coverage, screening and vaccinating adolescent girls and women of childbearing age is the priority. ^[7][8]
• In outbreak areas, refugees and under-immunised communities should be targeted first. ^[6]

• Measles, mumps and rubella are three preventable RNA viruses spread by respiratory droplets and aerosols, prevented by MMR.
• Measles is the most contagious, with incubation 11 to 12 days to prodrome and rash at about 14 days, Koplik spots before the rash, and a descending maculopapular rash lasting 5 to 6 days. ^[1][4]
• Mumps incubates 16 to 18 days and causes parotid swelling; orchitis occurs in about 30% of unvaccinated but 6% of vaccinated post-pubertal males. ^[2]
• Rubella incubates 14 days, is often subclinical, and usually mild, but early pregnancy infection carries about a 90% chance of fetal infection and CRS. ^[3][7]
• Measles complications include pneumonia, otitis media, diarrhoea, encephalitis (about 1 in 1,000), SSPE and death (1 to 3 per 1,000 children). ^[4][8]
• Mumps complications (meningitis, encephalitis, pancreatitis, hearing loss) are 1% or less in the vaccine era; permanent sequelae are rare. ^[2]
• Rubella complications include encephalitis (1 in 6,000) and thrombocytopenia (1 in 3,000); CRS is the most important outcome. ^[3][8]
• Communicability: measles 4 days before to 4 after rash; mumps 2 days before to 5 after parotitis; rubella 7 days before to 7 after rash; CRS infants shed virus up to 1 year. ^[1][2][3][7]
• Vaccination works: measles seroconversion about 95% after one dose and over 99% after two; rubella at least 95% after one; mumps about 94% after one, effectiveness about 78% (one dose) and 88% (two doses). ^[1][2][3]
• Routine schedule: 12 to 15 months and 4 to 6 years, minimum age 12 months, minimum interval 4 weeks for MMR. ^[1][2][3]
• Measles vaccine never substitutes for vitamin A in acute treatment; vitamin A for children under 5: 50,000, 100,000 or 200,000 IU depending on age, two doses. ^[4][6]
• MMR is contraindicated in pregnancy, severe immunocompromise and severe allergy; pregnancy should be avoided for 4 weeks. ^[1][2][3]
• Measles post-exposure vaccine may help in limited-contact settings within 72 hours but not in intense household contact; immune globulin has specific indications. ^[8]

Measles is covered in the respiratory and infectious-disease curriculum alongside pneumonia, otitis media and immunisation. Mumps-related orchitis relates to testicular disease. Rubella prevention connects to prenatal care and hearing screening. These are plain-text cross-references for now (other MedGrasp topics on immunisation, contraception and paediatric hearing screening are not yet linked here).

Guidelines cited: CDC Pink Book 14th edition chapter updates (2024) for measles, mumps and rubella; CDC Clinical Overview of Measles (2025/2026); CDC public-health outbreak guidance (2026); WHO Measles and Rubella fact sheets (15 July 2026); ACIP compendium MMWR 2013. Maternal and child health recommendations are consistent with WHO and CDC; regional schedules should be checked locally.