MMR vaccine is a combined vaccine to protect children against
, which are dangerous and potentially deadly diseases. Alternative names
, mumps vaccination, vaccine-MMR.
The MMR, which does not contain mercury, consists of live viruses that
have been weakened (attenuated) so that the vaccine is still capable of
inducing a productive immune response but does not cause the disease that
the original or "wild-type" viruses can. The MMR vaccine is
a mix of three vaccines: attenuvax (measles), mumpsvax (mumps), and
meruvax II (rubella).
The three-in-one MMR vaccine protects against measles, mumps, and rubella.
Although single antigen (individual) vaccines are available for each part
of the MMR, they are only used in specific situations, in which one of the
three diseases occurs and public health officials decide to immunize
infants six to 15 months of age for that particular disease. (Single
antigen vaccines pose less risk to children younger than the recommended
age of 15 months for the MMR.)
Before vaccination, epidemics of measles peaked in the spring every two to
four years. Measles is an endemic disease in many undeveloped countries
and in countries where measles immunization levels are low. Because the
risk of contracting measles in other countries is greater than in the
United States, infants and children should be as well protected as
possible before traveling.
Measles is caused by a virus that grows in the nose, mouth, throat, and
the eyes, and in their secretions. It is highly communicable and may not
be recognized early because the symptoms often resemble cold symptoms. The
incubation period is 10 to 11 days. Measles begins with slight temperature
rise and a runny nose and eyes. About the second or third day, blush-white
pinpoint spots with a red rim, known as Koplick's spots, appear in
the mouth. Small dark red pimples appear on the head and spread gradually
over the body. These pimples grow larger and in groups, giving a blotchy
appearance, which is an important difference between measles and
. In scarlet fever, the skin appears red all over.
The respiratory symptoms grow worse. The child sneezes often, the eyes are
sore, and nasal secretion becomes purulent. Light hurts the eyes
(photophobia). The child's throat is sore. The rash is greatest
about the fourth day, and it may last up to ten days. During the second
week, the skin begins to flake off, and it continues to do so for five to
Treatment is limited to combating the symptoms of measles because
as of 2004 are ineffective. The disease has serious possible
complications. For example, encephalomyelitis (inflammation of the brain
and spinal cord) occurs in one to two cases out of 1000 patients; the
disease is fatal at that same rate. Immune globulin injections help
prevent or reduce measles infection if given within six days of exposure.
Complications can be brought on by measles.
occurs in one out of 6000 cases; 20 percent of these infections are
fatal. Thrombocytopenic purpura (skin hemorrhages because of decreased
) occur in one out of 3000 cases.
Mumps, another viral disease, affects the salivary glands, especially the
parotid gland. Children under the age of two years old seldom have mumps;
adults rarely have this disease. A closer contact is necessary to transmit
mumps than other contagious diseases. The incubation period lasts from two
to three weeks, averaging about 18 days.
In most cases, the first sign of mumps is a swelling in the parotid
glands; occasionally, mumps may begin with a slight fever,
, and malaise before the swelling appears. Sometimes only one of the
parotid glands is affected, but both may be inflamed at the same time or
one after the other. The glands become swollen and tender and are painful.
It hurts for the child to suck while nursing or in older children to open
his mouth and eat, but otherwise he may not feel sick at all. After two or
three days, the swelling begins to go down, and usually disappears by the
tenth day. As a rule, keeping children isolated or out of school for two
weeks is long enough to prevent communicating the infection to others.
Treatment is entirely palliative; as of 2004, there was no effective
Mumps can cause certain complications. The nervous system is affected in
65 percent of patients; 10 percent display symptoms of this, and 2 percent
of these cases are fatal. Testicular complications occur in 14 to 35
percent of post-pubertal boys, and complications regarding the ovaries in
7 percent of post-pubertal females. These complications are rare in
prepubescent children, however. Deafness in one or both ears occurs in one
out of 15,000 cases. More than half of the deaths from mumps occur in
those over 19 years of age. Mumps infection during the first trimester of
pregnancy increases the risk of spontaneous abortion.
Rubella is also caused by a virus, but the disease is mild and last only a
short time. The symptoms are like measles but are not nearly as severe,
and spots never appear on the mucous membranes of the mouth. Sometimes the
rash that appears on the face is the first noticeable sign of a rubella
infection. The rash spreads quickly and disappears just as rapidly;
sometimes it is gone from the face and the neck by the time it reaches the
arms and the legs. The rash usually lasts two to four days.
Isolation from other children is brief or not carried out at all; since
the infectious stage is so brief, there is little danger of passing on the
infection after the rash appears. The greatest risk of German measles is
fetal malformations which occur when a mother is infected in the early
months of pregnancy.
Children and adults may can have rubella more than once; 3 to 10 percent
of those who have had rubella and 14 to 18 percent of those immunized
become infected on exposure to the virus. Some reinfections are
subclinical (i.e., have no visible symptoms). In fact, some 25 to 50
percent of rubella infections are asymptomatic.
Because the risk of serious disease from infection with either mumps or
rubella in infants is low, mumps and rubella vaccines should not be given
to infants younger than 12 months old. When the measles vaccine is needed
a single-antigen measles vaccine is given. However, parents of an infant
less than 12 months of age should be immune to mumps and rubella so they
will not expose the infant or become infected if the infant becomes ill.
The first dose of the vaccine is given to children 12 to 15 months old.
The second dose of the MMR vaccine should be given at four to six years of
age. All children are to be fully immunized before starting school in the
United States. Children who have not the second dose as recommended should
complete the immunization by 11 or 12 years of age.
Before infants and children of 12 months of age or older leave the United
States, they should receive two doses of MMR vaccine separated by at least
28 days, with the first dose given on their birthday. Infants under 12
months of age should receive a dose of monovalent (single antigen) measles
vaccine before departure. If monovalent vaccine is not available, no
specific contraindication exists to giving MMR to infants six to eleven
months of age. The risk for serious disease from either mumps or rubella
infection among infants is low.
Infants who receive the monovalent measles vaccine or MMR before their
first birthday are vulnerable to all three diseases and should be
revaccinated with two doses of MMR. The first should be given when the
infant is 12 to 15 months of age (12 months if the infant remains in an
area where disease risk is high) and the second at least 28 days later.
Parents or adults who travel or live abroad with infants less than 12
months old should have evidence of immunity to rubella and mumps, as well
as measles, to
avoid becoming infected if the infants are exposed to the diseases.
An infant less than six months of age is usually protected against
measles, mumps, and rubella by maternal antibodies. As a rule, the infant
does not need added protection unless the mother is diagnosed with
Most fetuses receive some natural immunity to measles from their mothers
in utero. This passive immunity fades over time and is less effective in
children of immunized mothers than in children of mothers who had the
The duration of protection is dependent to a great extent on the maternal
antibody titer and the antibodies received by the infant during pregnancy.
Women who have had the disease have higher measles antibody titers than
women who have not had measles but have been vaccinated. Women who have
not had measles nor vaccination have no measles antibodies.
There are few reasons not to be vaccinated. Some of these are as follows:
Most of the time inactivated vaccines are given intramuscularly (IM), and
live virus vaccines are given subcutaneously (SC). Vaccines that are used
intramuscularly may cause local reactions (such as irritation, skin
discoloration, inflammation, and granuloma formation) if injected into
subcutaneous tissue. The vaccine may also be less effective if it is not
given by the proper route.
—Without whole cells. An acellular vaccine contains on parts of
the cells which can produce immunity in a person receiving the vaccine.
—Produced by the body when the immune system is triggered to
produce antibodies, either by immunization or a disease.
—A negative side effect of a vaccine.
—Also called anaphylactic shock; a severe allergic reaction
characterized by airway constriction, tissue swelling, and lowered blood
—Inflammation of the brain, usually caused by a virus. The
inflammation may interfere with normal brain function and may cause
seizures, sleepiness, confusion, personality changes, weakness in one or
more parts of the body, and even coma.
—The time period between exposure to an infectious agent, such as
a virus or bacteria, and the appearance of symptoms of illness. Also
called the latent period.
—Pain, redness, swelling, and heat that develop in response to
tissue irritation or injury. It usually is caused by the immune
system's response to the body's contact with a foreign
substance, such as an allergen or pathogen.
—The body reception of proteins that act as antibodies instead of
making the antibodies itself. Immunoglobulins may produce this immunity.
All babies have antibodies from their mothers, which give them
Parents often express concern about combining three vaccines in one
injection. As of 2004 there is no published evidence showing a benefit to
combination MMR vaccine into three individual shots. The CDC continues to
recommend two doses of the combined MMR vaccine for all children.
Because signs of
may appear around the time children receive the MMR vaccine, some parents
worry that the vaccine causes autism. Research has not found a
relationship between MMR vaccine and autism.
It is sometimes difficult for parents to adhere to the recommended vaccine
schedule, including the spacing between doses. If the intervals between
doses is longer than usual, there is no need to restart the series of any
MMR vaccinations are appropriate for children with chronic diseases such
as diabetes and cardiovascular condition as advised by the pediatrician.
Symptoms of low-grade fever, irritability, and soreness at the injection
site following the MMR immunization can be relieved with an analgesic such
as acetaminophen as recommended by the pediatrician. Cool compresses to
the injection site are also comforting.
Behrman, Richard E., et al., eds.
Nelson Textbook of Pediatrics
, 16th ed. Philadelphia: Saunders, 2000.
A Jab in the Dark: Anxiety and Rationality in the MMR Controversy.
New York: New York Review of Books, 2005.
"Childhood Immunization Support Program."
American Academy of Pediatrics.
Available online at http://www.cispimmunize.org/ (accessed
December 18, 2004).