Measles: Questions and Answers

Information about the disease and vaccines

What causes measles? How do I know if my child has measles?

Measles is caused by a virus. Measles is diagnosed by a combination of the
patient’s symptoms and by laboratory tests.
How does measles spread?
Measles is spread through the air by infectious drop- Is there a treatment for measles?
lets and is highly contagious. There is no specific treatment for measles. People
with measles need bed rest, fluids, and control of
How long does it take to show signs of measles after fever. Patients with complications may need treat-
being exposed? ment specific to their problem.
It takes an average of 10-12 days from exposure to
the first symptom, which is usually fever. The How long is a person with measles contagious?
measles rash doesn’t usually appear until approxi- Measles is highly contagious and can be transmitted
mately 14 days after exposure, 2-3 days after the from four days before the rash becomes visible to
fever begins. four days after the rash appears.

What are the symptoms of measles? If I think my child has been exposed to measles,
Symptoms include fever, runny nose, cough, loss of what should I do?
appetite, “pink eye,” and a rash. The rash usually You should contact your doctor immediately if you
lasts 5-6 days and begins at the hairline, moves to believe you or your child has been exposed to
the face and upper neck, and proceeds down the measles. If your child has not been vaccinated,
body. measles vaccine may prevent disease if given within
72 hours of exposure. Immune globulin (a blood
How serious is measles? product containing antibodies to the measles virus)
Measles can be a serious disease, with 30% of re- may prevent or lessen the severity of measles if given
ported cases experiencing one or more complica- within six days of exposure.
tions. Death from measles occurs in approximately
2 per 1,000 reported cases in the United States. How common is measles in the United States?
Complications from measles are more common Before the vaccine was licensed in 1963, there were
among very young children (younger than five years an estimated 3-4 million cases each year. In the years
of age) and adults (older than 20 years of age). following 1963, the number of measles cases
dropped dramatically, with only 1,497 cases in 1983,
What are possible complications from measles? the lowest annual total reported up to that time.
Diarrhea is the most common complication of
A measles epidemic occurred in the U.S. from large
measles (occurring in 8% of cases), especially in
outbreaks in many cities. From 1989 to 1991, 55,622
young children. Ear infections occur in 7% of re-
cases were reported with a total of 123 measles-as-
ported cases. Pneumonia, occurring in 6% of re-
sociated deaths. Half of the cases and deaths were
ported cases, accounts for 60% of measles-related
in children younger than five years of age. The most
deaths. Approximately one out of one thousand
important cause of this epidemic was low vaccina-
cases will develop acute encephalitis, an inflamma-
tion rates among preschool-age children.
tion of the brain. This serious complication can lead
to permanent brain damage. Due to extensive vaccination efforts, the number of
reported measles cases fell during the 1990s. Only
Measles during pregnancy increases the risk of pre-
37 cases were reported in 2004. It appears that
mature labor, miscarriage, and low-birth-weight in-
measles transmission in the United States has been
fants, although birth defects have not been linked to
interrupted. However, measles is still common in
measles exposure.
many other countries in the world and can easily be
Measles can be especially severe in persons with imported, so continued vaccination against the dis-
compromised immune systems. Measles is more se- ease is still important.
vere in malnourished children, particularly those
with vitamin A deficiency. In developing countries,
the case-fatality rate may be as high as 25%. Page 1 of 4

Technical content reviewed by the Centers for Disease Control and Prevention, February 2007. www.vaccineinformation.org/catg.d/p4209.pdf • Item #P4209 (2/07)

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 Page 2 of 4

Can you get measles more than once? After two doses of measles vaccine, 99% of persons
No. become immune to the disease.

When did measles vaccine become available? Which adolescents and adults should receive the
Measles vaccine became available in 1963. An im- MMR vaccine?
proved measles vaccine became available in 1968. In general, adults born before 1957 are likely to
Combination measles-mumps-rubella (MMR) vac- have had measles, mumps, and rubella during child-
cine became available in 1971. Combination hood and so are assumed to be immune. Exceptions
measles-mumps-rubella-varicella (MMRV) vaccine to this guideline are women who want to become
became available in 2005. pregnant (see rubella section) and persons who
work in medical facilities (see next question).
What kind of vaccine is it?
All persons born in or after 1957 should be immune
Measles vaccine is a live, attenuated (or weakened)
to measles by having had one or more doses of MMR
strain of the measles virus grown in chick embryo
vaccine, a blood test that indicates immunity to
tissue culture. In the United States, it is recom-
measles, or written documentation of measles dis-
mended that it be given as part of the MMR vaccine,
ease diagnosed by a doctor. Certain groups of people
which protects against measles, mumps, and rubella
born in or after 1957 are at increased risk for expo-
(German measles) or the MMRV vaccine (MMR plus
sure to measles and must be certain to be immune
varicella (chickenpox) vaccine) when age-appropri-
to measles. These adults are those attending college
ate (licensed for use only from age 12 months
or other post-high school educational institutions,
through age 12 years).
persons who work in medical facilities, and interna-
How is this vaccine given? tional travelers. These adults should receive two
This vaccine is a shot given subcutaneously (in the doses of MMR or have other evidence of measles
fatty layer of tissue under the skin). immunity (lab test or physician-diagnosed measles).

Who should get this vaccine? Why do healthcare workers need proof of immunity
Two doses of measles vaccine (given as combination to measles?
MMR or MMRV when age-appropriate) are recom- Persons who work in medical facilities are at much
mended for all children and certain adolescents and higher risk for being exposed to measles than is the
adults. general population (most people with measles are
quite ill and will visit a medical facility at some point
At what age should the first MMR/MMRV shot be during their illness). Making sure that all workers
given? are immune to this disease protects both the em-
The first dose of MMR or MMRV should be given on ployee and the patients with whom he or she may
or after the first birthday; the recommended range have contact. All persons working in a healthcare
is from 12-15 months. A dose given before 12 facility in any capacity should have evidence of im-
months of age may not be counted, so the child’s munity to measles, including full- or part-time em-
medical appointment should be scheduled with this ployees, medical or non-medical, paid or volunteer,
in mind. students, and those with or without direct patient
responsibilities.
When should children get the second MMR/MMRV
Healthcare workers should have one of the follow-
shot?
The second dose is usually given when the child is ing: documentation of two doses of MMR vaccine
4-6 years old, or before he or she enters kindergar- (or two doses of a live measles-containing vaccine,
ten or first grade. However, the second dose can be two doses of a live mumps-containing vaccine, and
given anytime as long as it is at least four weeks af- at least one dose of a live rubella-containing vac-
ter the first dose. MMRV can only be given through cine), a laboratory test that indicates immunity, or
age 12 years. written evidence of previous measles disease diag-
nosed by a physician.
How effective is this vaccine?
The first dose of MMR vaccine produces immunity Who recommends this vaccine?
to measles in 95-98% of children vaccinated. The The Centers for Disease Control and Prevention
reason for the second dose is to protect those per- (CDC), the American Academy of Pediatrics (AAP),
sons who did not become immune after one dose. the American Academy of Family Physicians (AAFP),

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 Page 3 of 4

and the American College of Physicians (ACP) have Severely immunocompromised persons should not
all recommended this vaccine. be given MMR vaccine. This includes persons with
conditions such as congenital immunodeficiency,
How safe is this vaccine? AIDS, leukemia, lymphoma, generalized malig-
Hundreds of millions of doses of measles vaccine nancy, and those receiving treatment for cancer with
have been given in the United States, and its safety drugs, radiation, or large doses of corticosteroids.
record is excellent. Because it is a live vaccine, side Household contacts of immunocompromised people
effects following vaccination can be similar to a very should be vaccinated according to the recommended
mild case of measles. More than 80% of children will schedule.
have no side effects at all.
Although persons with AIDS or HIV infection with
What side effects have been reported with this vac- signs of serious immunosuppression should not be
cine? given MMR, persons with HIV infection without
Fever is the most common side effect, occurring in symptoms can and should be vaccinated against
5%-15% of vaccine recipients. About 5% of persons measles.
develop a mild rash. When they occur, fever and rash
appear 7-10 days after vaccination. About 25% of Can individuals with egg allergy receive MMR vac-
cine?
adult women receiving MMR vaccine develop tem-
In the past it was believed that persons who were
porary joint pain, although this symptom is related
allergic to eggs would be at risk of an allergic reac-
to the rubella component of the combined vaccine.
tion from the vaccine because the vaccine is grown
Joint pain only occurs in women who are not im-
in tissue from chick embryos. However, recent stud-
mune to rubella at the time of vaccination. MMR
ies have shown that this is not the case. Therefore,
vaccine may cause thrombocytopenia (low platelet
MMR may be given to egg-allergic individuals with-
count) at the rate of about 1 case per 30,000-40,000
out prior testing or use of special precautions.
vaccinated people. Cases are almost always tempo-
rary and benign. Does the MMR vaccine cause autism?
More severe reactions, including allergic reactions, There is no scientific evidence that measles, MMR,
are rare. About one person per million develops in- or any other vaccine causes autism. The question
flammation of the brain, which is probably caused about a possible link between MMR vaccine and
by the measles vaccine virus. autism has been extensively reviewed by indepen-
dent groups of experts in the U.S. including the
If my child develops a rash after getting the MMR National Academy of Sciences’ Institute of Medicine.
vaccine, is he contagious? These reviews have concluded that the available
Transmission of the measles vaccine virus does not epidemiologic evidence does not support a causal
occur from a vaccinated person, including those who link between MMR vaccine and autism.
develop a rash. No special precautions (e.g., exclu-
sion from school or work) need be taken. The MMR-autism theory had its origins in research
by Andrew Wakefield and colleagues in England.
Who should NOT receive measles vaccine? They suggested that inflammatory bowel disease
Anyone who experiences a severe allergic reaction (IBD) is linked to persistent viral infection. In 1993,
(e.g., generalized hives, swelling of the lips, tongue, Wakefield and colleagues reported isolating measles
or throat, difficulty breathing) following the first virus in the intestinal tissue of persons with IBD. The
dose of MMR should not receive a second dose. validity of this finding was later called into question
Anyone knowing they are allergic to an MMR com- when it could not be reproduced by other research-
ponent (gelatin, neomycin) should not receive this ers.
vaccine. The studies that suggest a cause-and-effect relation-
As with all live virus vaccines, women known to be ship exists between MMR vaccine and autism have
pregnant should not receive the MMR vaccine, and received a lot of attention by the media. However,
pregnancy should be avoided for four weeks follow- these studies have significant weaknesses and are far
ing vaccination with MMR. However, women who outweighed by many population studies that have
are breast-feeding can be vaccinated. Children and consistently failed to show a causal relationship be-
other household contacts of pregnant women should tween MMR vaccine and autism. In addition, the
be vaccinated according to the recommended sched- findings were further discredited when an investiga-
ule.

Immunization Action Coalition • St. Paul, MN 55104 • (651) 647-9009 • www.vaccineinformation.org • www.immunize.org
 Page 4 of 4

tion found that Wakefield did not disclose he was with links to journal article abstracts: http://
being funded for his research by lawyers seeking www.immunize.org/mmrautism
evidence to use against vaccine manufacturers. For more information, visit CDC’s “Vaccines and
For a summary of the issues on this topic, please Autism Theory” web page at www.cdc.gov/od/sci-
read “Vaccines and Autism,” by Paul A. Offit, MD, ence/iso/mmr_autism.htm
Director, Vaccine Education Center, Children’s Hos-
pital of Philadelphia. This article can be accessed Can the vaccine cause measles?
online at: www.immunize.org/catg.d/p2065.htm As mentioned above, because the measles vaccine is
“live,” it can cause mild measles-like symptoms in
“Does MMR vaccine cause autism? Weigh the evi-
some recipients, but it does not cause measles dis-
dence” lists all the major studies related to this issue
ease.

Immunization Action Coalition • St. Paul, MN 55104 • (651) 647-9009 • www.vaccineinformation.org • www.immunize.org