Vaccination introduces a vaccine into the body to produce immunity and
prevent specific diseases.
Many diseases that once caused widespread illness, disability, and death
are now prevented by vaccines in developed countries. Vaccines are
medicines that contain weakened or dead bacteria or viruses. When a child
receives a vaccine, his or her immune system responds by producing
antibodies, substances that weaken or destroy disease-causing organisms.
When the child comes in contact with live bacteria or viruses of the same
kind that are in the vaccine, the antibodies prevent those organisms from
making the child sick. Vaccines also stimulate the cellular immune system.
In other words, the child becomes immune to the disease the organisms
normally cause. Building immunity by using a vaccine is called
immunization. Childhood immunizations are safe and remain the most
effective way to prevent disease.
Vaccines contain antigens (weakened or dead viruses, bacteria, and fungi
that cause disease and infection). When introduced into the body, the
antigens stimulate the immune system response by instructing B cells to
produce antibodies, with assistance from T-cells. The antibodies are
produced to fight the weakened or dead viruses in the vaccine. The
antibodies "practice" on the weakened viruses, preparing the
immune system to destroy real and stronger viruses in the future. When new
antigens enter the body, white blood cells (called macrophages) engulf
them, process the information contained in the antigens, and send it to
the T-cells so that an immune system response can be mobilized.
In the early 2000s, children in the United States and in other developed
countries routinely have a series of vaccinations that begins at birth.
Vaccinations in children began about 1900 with the smallpox vaccine. In
1960 there were only five vaccines in eight shots. The number of
vaccinations children receive has steadily increased since that time. As
of 2004, children receive 11 different vaccines given in up to 20 shots by
age two years. Given according to a specific schedule, these vaccinations
, pertussis (
(German measles); varicella (
; pneumococcus; and
type B (Hib disease, a major cause of spinal
) and, in some states,
. This series of vaccinations is recommended by the American Academy of
Family Physicians, the American Academy of Pediatrics, and the Centers for
Disease Control and Prevention and is a requirement in all states before
children can enter school. States make exceptions for children who have
medical conditions such as
that prevent them from having vaccinations, and some states also make
exceptions for children whose parents object for religious or other
Several vaccines are delivered in one injection, such as the
measles-mumps-rubella (MMR) and diphtheria-tetanus-pertussis (DTP)
Vaccines are used in several ways. Some vaccines, such as the
, are given only when a child comes in contact with the virus that causes
the disease, such as through a dog bite.
Recommendations for other vaccines and immunobiologic medicines depend on
the child's health status or area of world where the family might
travel. Such treatments are vaccine or immune globulin for hepatitis A,
typhoid, meningitis, Japanese
In addition the uses discussed above, vaccines are available for
preventing anthrax, cholera, plague,
, and yellow fever. Most vaccines are given as injections, but a few are
The administration of vaccines to meet travel requirements should not
interfere with or postpone any
Recommended childhood and adolescent immunization schedule, United
(Graph by GGS Information Services.)
of the routine childhood immunizations. If necessary, the routine
immunization schedule can be accelerated to give as many vaccines as
possible before departure. Decisions about vaccinations for children with
chronic illnesses are made with the child's doctor.
Parents who are planning to travel with children to another country should
find out what vaccinations are needed. Some vaccinations may be needed 12
weeks before the trip, so getting this information early is important.
Many major hospitals and medical centers have travel clinics that provide
this information. The traveler's health section of the Centers for
Disease Control and Prevention also has information on vaccination
A vaccination health record helps parents and healthcare providers keep
track of a child's vaccinations. The record should start when the
child has his or her first vaccination and should be kept up-to-date with
each added vaccination. While most doctors follow the recommended
vaccination schedule, some flexibility is allowed. For example,
vaccinations scheduled for age two months may be given anytime between six
to ten weeks. Slight departures from the schedule do not keep the child
from developing immunity, as long as all the vaccinations are received
close to the right times.
Vaccines are not always effective, and there is no way to predict whether
a vaccine will "take" in any particular child. To be most
effective, vaccination programs depend on the whole community
participating. An increase in the number of vaccines given to children and
the increased percentage of children receiving vaccines has resulted in a
dramatic decrease in the number of vaccine-preventable diseases. In the
United States, most young parents as of 2004 had never seen many of
diseases that vaccines prevent. Even people who do not develop immunity
through vaccination are safer because their friends, neighbors, children,
and coworkers are immunized.
Factors influencing recommendations for childhood vaccination include
age-specific risks of disease and
complications, the ability of a given age group to respond to the
vaccine, and the potential interference with the immune response to
transferred maternal antibody. There are vaccines for the youngest age
group at risk for developing the disease and known to develop a
satisfactory antibody response to the vaccination.
Like most medical procedures, vaccination has risks as well as great
benefits. When children receive a vaccine, parents should be told about
both. Questions or concerns should be discussed with a doctor or other
healthcare provider. The Centers for Disease Control and Prevention,
located in Atlanta, Georgia, is also a good resource for information.
Vaccines may cause problems for children with certain
. Children who are allergic to the
neomycin or polymyxin B should not take rubella vaccine, measles vaccine,
mumps vaccine, or the combined measles-mumps-rubella (MMR) vaccine.
Children who have had a severe allergic reaction to baker's yeast
should not take the
hepatitis B vaccine
. Patients who are allergic to antibiotics such as gentamicin sulfate,
streptomycin sulfate, or other amino glycosides should check with their
doctors before the taking influenza vaccine, as some influenza vaccines
contain small amounts of these drugs. Also, some vaccines, including those
for influenza, measles, and mumps, are grown in the laboratory in fluids
of chick embryos, and should not be given to children who are allergic to
eggs. In general, parents of children who have had an unusual reaction to
a vaccine in the past should report the reaction to the doctor before
taking the same vaccine again. Doctors need to know about allergies to
foods, medicines, preservatives, or other substances.
Children with other medical conditions should be given vaccines with
caution. Influenza vaccine may reactivate Guillain-Barre syndrome (GBS) in
patients who have had it before. This vaccine also may worsen illnesses
that involve the lungs, such as
. Vaccines that cause fever as a side effect may trigger seizures in
people who have a history of seizures caused by fever.
Certain vaccines are not recommended during pregnancy. However, women who
are at risk of getting specific disease such as polio may receive the
vaccine to prevent medical problems in their babies. Vaccinating a
pregnant woman with tetanus toxoid can prevent tetanus in the baby at
Women should avoid becoming pregnant for three months after taking rubella
vaccine, measles vaccine, mumps vaccine, or the combined
measles-mumps-rubella (MMR) as these vaccines may cause problems in the
Women who are breastfeeding should check with their doctors before taking
Most side effects from vaccines are minor and easily treated. The most
, redness, and swelling at the injection site. Some children may also
develop a fever or a rash. Rarely, vaccines may cause severe allergic
reactions, swelling of the brain, or seizures. Unusual reaction after
receiving a vaccine should be reported to the doctor right away.
Vaccines may interact with other medicines and medical treatments. When
this happens, the effects of the vaccine or the other medicine may change
or the risk of side effects may be greater. Radiation therapy and cancer
drugs may reduce the effectiveness of many vaccines or may increase the
chance of side effects. Parents should let the doctor know of all
medicines taken by the child and learn whether the possible interactions
could interfere with the therapeutic effects of the vaccine or the other
—A bacterial infection, primarily of livestock, that can be
spread to humans. In humans it affects the skin, intestines, or lungs.
—A special protein made by the body's immune system as a
defense against foreign material (bacteria, viruses, etc.) that enters
the body. It is uniquely designed to attack and neutralize the specific
antigen that triggered the immune response.
—Singluar, bacterium; tiny, one-celled forms of life that cause
many diseases and infections.
—An infection of the small intestine caused by a type of
bacterium. The disease is spread by drinking water or eating foods that
have been contaminated with the feces of infected people. It occurs in
parts of Asia, Africa, Latin America, India, and the Middle East.
Symptoms include watery diarrhea and exhaustion.
—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 solid waste, also called stool, that is left after food is
digested. Feces form in the intestines and pass out of the body through
—Progressive and usually reversible paralysis or weakness of
multiple muscles usually starting in the lower extremities and often
ascending to the muscles involved in respiration. The syndrome is due to
inflammation and loss of the myelin covering of the nerve fibers, often
associated with an acute infection. Also called acute idiopathic
—The system of specialized organs, lymph nodes, and blood cells
throughout the body that work together to defend the body against
foreign invaders (bacteria, viruses, fungi, etc.).
—A process or procedure that protects the body against an
infectious disease by stimulating the production of antibodies. A
vaccination is a type of immunization.
—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.
—An infection or inflammation of the membranes that cover the
brain and spinal cord. It is usually caused by bacteria or a virus.
—An organism that is too small to be seen with the naked eye,
such as a bacterium, virus, or fungus.
—A single, independent unit of life, such as a bacterium, a
plant, or an animal.
—A serious, potentially life-threatening infectious disease
caused by the bacterium
. The disease is usually transmitted to humans by the bites of infected
rodent fleas. There are three major types: bubonic, pneumonic, and
—A sudden attack, spasm, or convulsion.
—Tuberculosis (TB) is a potentially fatal contagious disease that
can affect almost any part of the body, but is mainly an infection of
the lungs. It is caused by a bacterial microorganism, the tubercle
. Symptoms include fever, weight loss, and coughing up blood.
—A severe infection caused by a bacterium,
. People with this disease have a lingering fever and feel depressed and
exhausted. Diarrhea and rose-colored spots on the chest and abdomen are
other symptoms. The disease is spread through poor sanitation.
—A small infectious agent consisting of a core of genetic
material (DNA or RNA) surrounded by a shell of protein. A virus needs a
living cell to reproduce.
—An infectious disease caused by a virus. The disease, which is
spread by mosquitoes, is most common in Central and South America and
Central Africa. Symptoms include high fever, jaundice (yellow eyes and
skin) and dark-colored vomit, a sign of internal bleeding. Yellow fever
can be fatal.
Immunizations are not given when a child has signs of an acute illness. An
interrupted primary series of immunizations need not started again but may
simply continue after the child recovers. The child's doctor is the
best person to decide when each vaccination should be given.
The eventual goal in child care is to reduce stress. Parents should try to
increase the child's feeling of security and well-being by close
involvement with the immunization process. Providing explanations of the
immunization plan, special tests, and procedures suitable to the
child's age is helpful. Infants and toddlers are not likely to
understand verbal explanations, but they have a strong parental attachment
and need affection to ease fears. Small children also have an urgent need
for their mothers to defend them during medical treatments. Older children
may even protest or despair in getting an injection but are usually
accepting of reasonable explanations.
The health-care professional reviews the immunization record and the
health status of the child at each visit. If necessary the nurse or doctor
helps the parent correctly position the child and exposure of the
injection site. Parents should hold a small child on their laps securely
for the injection; older children may be put on the examination table in
the doctor's office. After the injection, parents can give the
child immediate comfort to control crying and then leave the treatment
Institute of Medicine Staff, et al.
Immunization Safety Review: Multiple Immunizations and Immune
Washington, DC: National Academy Press, 2002.
Kassianos, George C., et al.
Immunization: Childhood and Travel Health.
Oxford, UK: Blackwell Publishing Inc., 2001.
Parents Guide to Childhood Immunization.
Washington, DC: U.S. Government Publishing Office, 2001.
Studor, Hans-Peter, et al.
Vaccination: A Guide for Making Personal Choices.
Edinburgh, Scotland: Floris Books, 2004.
Centers for Disease Control National Immunization Program.
Available online at http://www.cdc.gov/nip (accessed December 3,
"Vaccination Recommendations for Infants and Children."
CDC Travelers' Health: Health Information for International
Available online at http://www.cdc.gov/travel/child-vax.htm
(accessed December 3, 2004).