In 2017, I had the unfortunate opportunity to experience my first outbreak of measles as an attending physician. I see the yearly influenza epidemic and the typical viral “bugs” that circulate throughout the year, but this was different. I live and practice in Minnesota at the epicenter of where a measles epidemic occurred. My clinic provides care for two populations that were at high risk during this outbreak: a large Somali-American population (which was the primary population affected) and children who were under-vaccinated due to parent refusal.
The impact of the outbreak was significant, not only for the children and adults who were exposed and infected with the disease, but also for the health care system and community as a whole. There was an increase in phone calls from concerned parents, an increase in vaccination visits, an increase in public health education and epidemiologic resources being used, and a lot of fear throughout the community, which led to people avoiding public places.
Working through this outbreak helped me realize how much misinformation is circulating and how the decision not to immunize one's own children affects an entire community. I thought a review of the measles and the MMR (measles, mumps, and rubella) and MMRV (measles, mumps, rubella, and varicella) vaccines would be helpful, as outbreaks are an increasingly common occurrence in the United States. Mumps and rubella are touched on as well, but the primary focus of this article is measles.
What Are Measles, Mumps, and Rubella?
Measles is a viral illness that causes an acute infection with a wide range of symptoms. The disease progresses through four phases: an incubation phase, a prodromal phase, a rash phase, and a resolution phase.1 The incubation phase lasts 9 to 10 days and is asymptomatic.1 During the prodromal phase, the patients are generally quite ill with fever, cough, coryza, malaise, and conjunctivitis.2 They can also develop more severe complications such as pneumonia, encephalitis, brain damage, and even death.2,3 The third phase is defined by a blanching erythematous macular rash that starts on the head and spreads downward.1,2 Patients also develop Koplik spots in the mouth, which are bluish-white papules with an erythematous halo and that are pathognomonic for measles.1,2 Measles is highly contagious and can be transmitted for about 4 days prior to development of the rash to 4 days after.1,4 The infection rate for susceptible people who are exposed is about 90%.1
Mumps is also an acute viral syndrome that is characterized by fever, body aches, parotid swelling, orchitis, oophoritis, and in rare cases aseptic meningitis and encephalitis.2,3 Mumps is easily spread in crowded environments such as classrooms, locker rooms, and dormitories, and is spread by exchange of saliva.5
Rubella, also known as the German measles, is an acute illness that is milder than measles and mumps. In children, there is often little to no fever or other symptoms, although adolescents and adults do get mild to moderate generalized viral symptoms.1 Up to 25% of infected people will have no symptoms at all but are still able to spread the disease.1 Rubella is characterized by a faint rash that begins on the face and spreads downward, along with sore throat, conjunctivitis, and mild fever.1,3 The primary concern regarding rubella relates to high rates of birth defects and fetal demise when pregnant women contract the disease.2,3 Some of the common birth defects seen are hearing loss, cataracts, cardiac disease, neurodevelopmental effects, intellectual disability, and even autism.2
History of Measles
One of the first written accounts of the measles disease is from a Persian doctor in the ninth century AD.6 It wasn't until 1757 that Francis Home, a Scottish physician, reliably demonstrated that measles was caused by infection.6 By the 1950s, more data were being collected and an estimated 3 to 4 million people in the US were becoming infected with the measles virus each year.6 Of those, about 400 to 500 patients died, 1,000 progressed to encephalitis, and 48,000 were hospitalized annually.6 Around this time, Drs. John Enders and Thomas Peebles isolated the virus, and in 1963 Enders licensed the first measles vaccine.6 By 1968, Dr. Maurice Hilleman began distributing a new and improved version of the vaccine.6 Just 3 years later, in 1971, the vaccine was combined with the mumps and rubella vaccines, MMR vaccine became the standard choice. The effects of mass vaccination became apparent in 1981 when there was a dramatic drop in measles cases, with 80% fewer reported cases than the previous year.6 In 1989, an outbreak of measles among vaccinated school children prompted the addition of a second dose of MMR prior to school entry.6 In the year 2000, endemic measles was declared eliminated from the US.6 Currently, we are seeing a resurgence of this once eliminated disease due to higher rates of international travel and poor vaccination rates, which allows the virus to spread quickly due to lack of herd immunity2,7 (Table 1).
Timeline of Measles and Vaccine Development
Recent Trends in Vaccination and Disease
One of the biggest factors contributing to the increase of measles outbreaks in the US is the rising rate of unvaccinated people. The largest numbers of unvaccinated populations live in rural areas; however, there are increasingly larger populations of unvaccinated people living in more urban areas, raising concern for rapid spread of disease through these densely populated and under-immunized communities.8
According to the 2015 National Immunization Survey, only 72.2% of children age 19 to 35 months were fully vaccinated per the recommendations of the Advisory Committee on Immunization Practices.8 There are currently 18 states that allow a nonmedical exemption (ie, philosophical belief exemption) for vaccines.8 Since 2009, 12 of these states have seen a rise in nonmedical exemptions from vaccines.8 These 12 states are Arkansas, Arizona, Idaho, Maine, Minnesota, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Texas, and Utah.8 Only three states in the US have an outright ban on nonmedical exemption from vaccines: Mississippi, California, and West Virginia.8 As a result, these states have some of the highest vaccination rates and lowest incidence of vaccine-preventable diseases.8 Policies are beginning to change across the US due to the escalating rates of vaccine-preventable disease in recent years. Whereas some states (like those stated above) are banning nonmedical exemptions altogether, others are making it more difficult to refuse vaccination, such as requiring parents to view an educational module prior to obtaining an exemption.8
As vaccination rates have dropped, there has been a related increase in outbreaks of measles in recent years (Table 2). In 2014, the US reported 667 measles cases from 27 states, making it the largest number of cases since measles was declared eradicated in 2000.7 Contributing to these numbers was a highly publicized outbreak that originated at the Disneyland theme park in Anaheim, CA.8 The epidemic likely occurred due to low measles vaccination rates in California at the time (only 50%–86% in those who were exposed to the virus).8 In response to this outbreak, California instituted a statewide ban on nonmedical exemptions for measles vaccination.8
Major Measles Outbreaks in Recent Years
Another large outbreak occurred in the year 2017 in Minnesota. The outbreak occurred primarily in the Somali-American population, most of which is not vaccinated against the measles. The Somali-American community was previously highly vaccinated against the measles, with rates as high as 90% in 2008;4 however, due to the spread of misinformation and propaganda about the MMR vaccine causing autism, concern and fear spread through the community, leading to a sharp decline in vaccination rates.4 By 2014, only about 35.6% of Somali-American children had received 1 dose of the MMR vaccine.4 These low rates allowed for the rapid spread of the disease once it was introduced to the community. In 2011, there was a smaller outbreak of about 21 cases of the measles in the same community, with vaccination rates at the time about 54%.4 The 2017 outbreak resulted in 65 confirmed cases, with 62 of them occurring in unvaccinated people (77% were children older than age 12 months who were eligible for the vaccine).4 The outbreak primarily affected children, with the average age being 21 months.4 It spread across three counties, five schools, 12 daycare centers, and two health care facilities.4 About 8,250 people were exposed to the virus, and 31% of those who tested positive required hospitalization.4 In response to this outbreak, there was a large increase in the number of MMR vaccines being given, with weekly doses increasing from 2,700 per week prior to the epidemic to about 9,964 per week during the outbreak.4
The measles vaccine is currently available in two forms: the MMR (measles, mumps, rubella) vaccine and the MMRV (measles, mumps, rubella, varicella) vaccine.9 They are both live attenuated vaccines.9 The vaccines are highly effective, with 1 dose of the vaccine providing 93% of people with immunity against measles, 78% with immunity against mumps, and 97% with immunity against rubella.9 A second dose increases those numbers to 97% for measles and 88% for mumps, and rubella remains at 97%.9 The second dose of the vaccine is given to “catch” the people who do not respond to the first dose.9 Two doses are considered to confer lifelong immunity to all three viruses; however, emerging data suggest there may be waning immunity to mumps as time passes.5
The first dose of the vaccine should be given between ages 12 and 15 months, and the second dose should be given between ages 4 and 6 years.10 There are special circumstances where these rules may change. Infants age 6 to 12 months who are traveling to high-risk areas should receive a dose prior to travel and will need 2 additional doses after age 12 months.10 For travel purposes, during outbreaks, and for other special circumstances, the second MMR dose may be given as soon as 28 days after the first dose.2,10 Timing of the vaccine is significant because it can affect how effectively the vaccine works. It is important to wait until after age 12 months for the first dose to allow for a decline in maternal antibodies, which can interfere with the uptake of the vaccine.2 Side effects may also increase slightly if given after age 15 months (particularly the risk of febrile seizure), endorsing the importance of obtaining vaccines according to the recommended schedule.3
The vaccine may also be given after exposure to the virus. For post-exposure prophylaxis for measles, the vaccine should be administered within 72 hours.10,11 Administration of immunoglobulin within the first 6 days may also provide some protection.10,11 Unfortunately, the vaccine is not helpful after exposure to mumps or rubella.2 During a mumps outbreak, however, it is recommended for those at high risk to obtain a third MMR vaccine to ensure coverage in those whose immunity may be waning.2,10 Mumps outbreaks can occur in highly vaccinated communities due to this possible decreased immunity, but high vaccination rates help to limit the size and duration of these outbreaks.5
Side Effects and Adverse Events
The MMR and MMRV vaccines are largely safe and effective, and although there are some possible side effects, the vaccine is much safer than getting the measles, mumps, or rubella viruses.3 There are, however, some contraindications and precautions that must be considered when administering the vaccine.
Contraindications to the vaccine are limited and rare. They include anaphylaxis to the vaccine, known severe immunodeficiency (chemotherapy, congenital severe immunodeficiency, long-term immunosuppressive therapy, HIV with immune compromise), and currently pregnant or trying to get pregnant.2,10 There are also precautions (meaning you can give the vaccine but there may be an increased chance of an adverse reaction or interference with development of immunity). These include moderate or severe illness (the effects of the illness could be confused with side effects of the vaccine), recent receipt of an antibody-containing blood product, history of thrombocytopenia, need for tuberculosis testing, and a personal or family history of seizures.2,10 Women should also not get pregnant for 4 weeks after getting the vaccine due to the risks related to the rubella component.10
Many people have misconceptions related to who can and cannot receive the vaccine. Many falsely believe that you cannot get the vaccine if the following are true: having an egg allergy, HIV infection without severe immune-compromise, breast-feeding, contact with pregnant people, immune-deficient family members, mild acute illness, previous local reaction to the vaccine, currently taking antibiotics, or babies born prematurely.2,10,11 It is important to educate families that none of these are contraindications and that vaccines should be given according to the recommended schedule.
There are several adverse effects that are associated with the MMR and MMRV vaccines. These are rare and must be weighed against the protective benefit of the vaccine.12 The most common of these are fever (5%–15%), rash (5%), lymphadenopathy (5%), sore arm, joint complaints (up to 25%, primarily in teens and adult women with no previous immunity), allergic reaction, immune thrombocytopenia (temporary and rarely severe), and febrile seizures.2,3,11,12 Of these, the most concerning to parents is often the risk of febrile seizure. It is important to note that the overall risk is still quite low but that the risk increases as children get older, so administration of the vaccine at the appropriate time lessens the risk.2,3 Febrile seizure in younger children is also higher with the MMRV compared with the MMR vaccine, so it is recommended to give the MMR before the age of 4 years, although the MMRV vaccine is appropriate for children older than age 4 years.2,3 There is also strong evidence that there is absolutely no association between the vaccine and autism.12
How Can We Increase Vaccination Rates?
There are several things that providers can do to increase vaccine rates and improve education surrounding vaccination. Studies show that open and honest communication between providers and parents relating to vaccination safety and an emphasis on vaccines as a routine part of health care promotes compliance with vaccine recommendations and decreases nonmedical exemptions.8 Although the importance of herd immunity is well known, it was found that approaching parents with the benefits of vaccination to the community did not change their views on vaccines.13 Focusing on the benefits to the individual child, however, did improve their view of vaccines.13 Knowing the community's trends with vaccination is also important. Being able to understand where families are obtaining their information will help providers be prepared to address concerns and questions in a way that will ease parent concerns and promote vaccination.
Several countries are also making it increasingly difficult to refuse vaccination. Countries such as France, Italy, and Australia have put into place measures that make vaccines compulsory or have instituted fines for parents who refuse to vaccinate their children.8 Making nonmedical exemption increasingly more inconvenient will provide opportunities to educate families and help improve vaccine compliance. This will ensure more widespread vaccination and increased herd immunity in communities across the US.8
Finally, forming a respectful working relationship with families can make a big impact. Gaining their trust and providing professional guidance can often reassure parents who are trying to make the best decision for their children. Offering personal examples can also be helpful. Informing patients about first-hand experiences with the effects of these diseases (eg, measles, bacterial meningitis, pertussis), knowing the most common side effects and how many people actually experience them, and providing reassurance about the decision you would make with your own child can go a long way. For instance, many parents ask their provider questions such as “did your child get this?” or “what would you tell your family member?” With my own patients, knowing that I would choose to vaccinate according to the recommended schedule helps to encourage the families to vaccinate their own children on time as well.
Vaccines are one of the greatest public health achievements in the past century.12 We have seen a drastic decline in vaccine-preventable diseases since the introduction of vaccines, and it is important that we do not allow these devastating illnesses to creep back into our communities. Because of misinformation, spread of this misinformation via social media and other means, and increasing concerns regarding exposure to just about everything, vaccines rates have decreased and the rates of many vaccine-preventable illnesses are on the rise. Through quality education, stricter regulation, and respectful relationships with patients, providers can reverse this trend and keep these dangerous illnesses at bay.
- Michaels MG, Nowalk AJ. Infectious disease: infectious exanthems. In: Zitelli BJ, McIntire SC, Nowalk AJ, eds. Atlas of Pediatric Physical Diagnosis. Philadelphia, PA: Saunders Elsevier; 2012:469–470.
- Drutz JE. Measles, mumps, and rubella immunization in infants, children, and adolescents. UpToDate. Hirsch Martin, ed. Accessed August 13, 2018. https://www.uptodate.com/contents/measles-mumps-and-rubella-immunization-in-adults?search=Measles,%20mumps,%20and%20rubella%20immunization&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1.
- Centers for Disease Control and Prevention. Measles, mumps, and rubella (MMR) vaccine safety. https://www.cdc.gov/vaccinesafety/vaccines/mmr-vaccine.html. Accessed August 1, 2018.
- Hall V, Banerjee E, Kenyon C. Measles outbreak-Minnesota April–May 2017. MMWR Morb Mortal Wkly Rep. 2017;66: 713–717. doi:10.15585/mmwr.mm6627a1 [CrossRef]
- Centers for Disease Control and Prevention. Mumps cases and outbreaks. https://www.cdc.gov/mumps/outbreaks.html. Accessed August 1, 2018.
- Centers for Disease Control and Prevention. Measles history. https://www.cdc.gov/measles/about/history.html. Accessed August 1, 2018.
- Centers for Disease Control and Prevention. Measles cases and outbreaks. https://www.cdc.gov/measles/cases-outbreaks.html. Accessed August 1, 2018.
- Olive JK, Hotez PJ, Damania A, Nolan MS. The state of the antivaccine movement in the United States: a focused examination of nonmedical exemptions in states and counties. PLoS Med.2018;15(6):e1002578. doi:. doi:10.1371/journal.pmed.1002578 [CrossRef]
- Centers for Disease Control and Prevention. About the vaccine. Accessed August 13, 2018. https://www.cdc.gov/vaccines/vpd/mmr/hcp/about.html.
- Centers for Disease Control and Prevention. Routine measles, mumps, and rubella vaccination. https://www.cdc.gov/vaccines/vpd/mmr/hcp/recommendations.html. Accessed August 1, 2018.
- Albon J. Immunoprophylaxis. In: Engorn B, Flerlage J, eds. The Harriet Lane Handbook. 20th ed. Philadelphia, PA: Saunders Elsevier; 2015:370–371.
- Maglione MA, Das L, Raaen L, Smith A, et al. Safety of vaccines used for routine immunization of US children: a systematic review. Pediatrics. 2014;134(2):325–337. doi:. doi:10.1542/peds.2014-1079 [CrossRef]
- Hendrix KS, Finnell SM, Zimet GD, Sturm LA, Lane KA, Downs SM. Vaccine message framing and parents' intent to immunize their infants for MMR. Pediatrics. 2014;134(3):e675–e683. doi:. doi:10.1542/peds.2013-4077 [CrossRef]
Timeline of Measles and Vaccine Development
||First written account of measles vaccine
||Francis Home demonstrates that measles is caused by infection
||Measles becomes a reportable disease
||John Enders and Thomas Peebles isolate the virus
||John Enders licenses the first measles vaccine
||Maurice Hilleman releases and improved vaccine
||Introduction of measles/mumps/rubella vaccine
||80% drop in measles cases from prior year
||Endemic measles declared eradicated in the US
||Resurgence of the measles virus
Major Measles Outbreaks in Recent Years
||3 large outbreaks in groups of unvaccinated people
||>30 countries had an increase in measles, and a large outbreak in France brought cases to the US
||11 outbreaks in the US
3 outbreaks involving >20 people
||23 outbreaks in the US
1 large outbreak involving 383 cases in the Amish community in Ohio
||Outbreak originated at Disneyland theme park in California
||Minnesota experienced outbreak of 63 individuals, largely in the under-vaccinated Somali-American population