Vaccines work by preparing the body to fight illness. Each contains either a dead
or a weakened germ (or parts of it) that causes a particular disease.
The body practices fighting the disease by making antibodies that recognize specific
parts of that germ. This permanent or longstanding response means that if someone
is ever exposed to the actual disease, the antibodies are already in place and the
body knows how to combat it and the person doesn't get sick. This is called immunity.
Since the start of widespread vaccinations in the United States, cases of once
common childhood illnesses like measles
and diphtheria have
dropped dramatically. Immunizations have protected millions of kids from dangerous
diseases and saved thousands of lives.
In fact, some diseases are so rare now that parents sometimes ask if vaccines for
them are even needed. But most diseases that can be prevented by vaccines do still
exist in the world, even in the United States, although they happen very rarely.
Will the Immune System Be Weaker By Relying on a Vaccine?
No, the immune system
makes antibodies against a germ, like the chickenpox
virus, whether it encounters it naturally or is exposed to it through a vaccine. Being
vaccinated against one disease does not weaken the immune response to another disease.
Can a Vaccine Give Someone the Disease It's Supposed to Prevent?
It's impossible to get the disease from any vaccine made with dead (killed)
bacteria or viruses or just part of the bacteria or virus.
Only those immunizations made from weakened (also called attenuated)
live viruses — like the chickenpox
(varicella) and measles-mumps-rubella
(MMR) vaccines — could possibly make a child develop a mild form of the
disease. But it's almost always much less severe than if a child became infected
with the disease-causing virus itself. However, for kids with weakened immune systems,
such as those being treated for cancer, these vaccines may cause problems.
The risk of disease from vaccination is extremely small. One live virus vaccine
that's no longer used in the United States is the oral polio vaccine (OPV). The success
of the polio vaccination
program has made it possible to replace the live virus vaccine with a killed virus
form known as the inactivated
polio vaccine (IPV). This change has completely eliminated the possibility of
polio disease being caused by immunization in the United States.
Why Should I Have My Child Immunized if All the Other Kids in School Are Immunized?
It is true that a single child's chance of catching a disease is low if everyone
else is immunized. But your child is also exposed to people other than just those
in school. And if one person thinks about skipping vaccines, chances are that others
are thinking the same thing. Each child who isn't immunized gives highly contagious
diseases one more chance to spread.
Although vaccination rates are fairly high in the United States, there's no reliable
way to know if everyone your child comes into contact with has been vaccinated, particularly
now that so many people travel to and from other countries. So the best way to protect
your kids is through immunization.
Can Getting So Many Vaccines at One Time Harm My Baby?
Babies have stronger immune systems than you might think, and they can handle far
more germs than what they receive from vaccines. In fact, the amount of germs in vaccines
is just a small percentage of the germs babies' immune systems deal with every day.
Sometimes, kids can have a reaction to a vaccine like a mild fever or rash. But
the risk of serious reactions is small compared with the health risks associated with
the often-serious diseases they prevent, and do not happen because the baby got several
vaccines at once.
A lot of consideration and research went into creating the immunization
schedule most doctors use, and it has been proven safe time and time again. Still,
some parents choose to use alternative schedules (spreading or "spacing out" vaccines)
because they're concerned about the number of shots their babies get at each checkup.
This is actually more likely to make a baby sick. Studies show that many babies on
alternative immunization schedules never get all the vaccines they need.
Plus, alternative schedules can be a real hassle. Spacing out vaccines over more
doctor visits means that you'll have to take your child to the doctor — and
your child will have to get a shot — more often.
Why Should My Child Get a Painful Shot if Vaccines Aren't 100% Effective?
Few things in medicine work 100% of the time. But vaccines are one of the most
effective weapons we have against disease — they work in 85% to 99% of cases.
They greatly reduce your child's risk of serious illness (particularly when more and
more people are vaccinated) and give diseases fewer chances to take hold in a population.
It can be hard to watch kids get a shot, but the short-term pain is nothing compared
with suffering through a potentially deadly bout of diphtheria,
Why Do Healthy Kids Need to Be Immunized?
Vaccinations are intended to help keep healthy kids healthy. Because
vaccines work by protecting the body before disease strikes, if you wait until your
child gets sick, it will be too late for the vaccine to work. The best time to immunize
kids is when they're healthy.
Can Immunizations Cause a Bad Reaction in My Child?
The most common reactions to vaccines are minor and include:
redness and swelling where the shot was given
soreness at the site where the shot was given
In rare cases, immunizations can trigger more serious problems, such as seizures
or severe allergic reactions.
If your child has a history of allergies to food or medicine, or has had a problem
with a vaccine before, let the doctor know before any vaccines are given. Every year,
millions of kids are safely vaccinated and very few experience serious side effects.
Research continually improves the safety of immunizations. The American Academy
of Pediatrics (AAP) now advises doctors to use a diphtheria, tetanus,
and pertussis vaccine that includes only specific parts of the pertussis cell instead
of the entire killed cell. This vaccine, called DTaP, has been associated with
even fewer side effects.
Do Immunizations or Thimerosal Cause Autism?
No. Numerous studies have found no link between vaccines and autism
(a developmental disorder that's characterized by mild to severe impairment of communication
and social interaction skills). Likewise, a groundbreaking 2004 report from the Institute
of Medicine (IOM) found that thimerosal (an organic mercury compound
that's been used as a preservative in vaccines since the 1930s) does not
Still, some parents have opted not to have their children immunized, putting them
at great risk of contracting deadly diseases.
The MMR vaccine, especially, has come under fire even though many scientific
reports have found no evidence linking the vaccine to autism. In fact, the study that
suggested a possible link between autism and the MMR vaccine was retracted in 2004
and the doctor who published it lost his medical license. Even before
it was discredited and declared fraudulent, the study was rejected by all major health
organizations, including the AAP, the National Institutes of Health (NIH), the Centers
for Disease Control and Prevention (CDC), and the World Health Organization (WHO).
There's also no reason to believe that thimerosal is linked to autism, according
to the 2004 IOM report. Still, in an effort to reduce childhood exposure to mercury
and other heavy metals, thimerosal began being removed from kids' vaccines in 1999.
Now, vaccines for infants and young children contain no or very little thimerosal.
And recent studies have not shown any cognitive and behavioral problems in babies
who might have received these thimerosal-containing vaccines.
So what could explain the increased rates of autism in recent years? For one thing,
there's a broader definition of autism that can be applied to more kids who show varying
degrees of symptoms. A greater awareness of the condition among health professionals
also has led to more diagnoses.
And although the number of children diagnosed with autism may be increasing, the
rates of MMR vaccination are not. In London, diagnoses of autistic disorders have
been on the rise since 1979, but rates of MMR vaccination haven't increased since
routine MMR vaccination began in 1988.
Also, the average age of diagnosis of autism has been found to be the same both
in children who have and who have not received the MMR vaccine. What many
researchers are discovering is that subtle symptoms of autism are often present before
a child's first birthday — sometimes even in early infancy — but often
go unnoticed until the symptoms are more obvious to parents.
Wasn't There a Problem With the Rotavirus Vaccine?
Rotavirus is one of
the most common causes of diarrhea in young children. In 1999, a rotavirus vaccine
was taken off the market because it was linked to an increased risk for intussusception,
a type of bowel obstruction, in babies.
However, two different rotavirus vaccines (RotaTeq and Rotarix) are now available
and are very safe. Some studies suggest that they have a very small increased risk
for intussusception, but that problem is rare. These vaccines have been shown to prevent
most cases of rotavirus infection and almost all of the severe cases.
The vaccine is now on the regular immunization schedule to be given orally to infants
as a liquid during standard vaccination visits — RotaTeq at ages 2 months, 4
months, and 6 months, or Rotarix at ages 2 months and 4 months. Your doctor will have
the most current information.
Do Vaccines Cause SIDS, Multiple Sclerosis, Or Other Problems?
There are concerns, many of which circulate on the Internet, linking some vaccines
to multiple sclerosis, sudden
infant death syndrome (SIDS), and other problems. To date, studies have failed
to show any connection between immunizations and these conditions. The number of SIDS
cases has actually fallen by more than 50% in recent years, whereas the number
of vaccines given yearly has continued to rise.
Why Do Kids Need Vaccines for a Disease That's Been Eliminated?
Diseases that are rare or nonexistent in the United States, like measles and polio,
still exist in other parts of the world. Doctors continue to vaccinate against them
because it's easy to come into contact with illnesses through travel — either
when Americans travel abroad or when people who aren't properly immunized come to
the United States.
In recent years, there have been measles outbreaks in many different states, even
though measles was declared eliminated from the U.S. in 2000. (Elimination means that
the disease has not been transmitted continuously for over a year, but it doesn’t
mean there aren't outbreaks.) These cases were mostly among people who did not get
vaccinated. Other preventable diseases that had recent outbreaks include whooping
cough (pertussis) and mumps.
It's only safe to stop vaccinations for a particular disease when that disease
has been eradicated worldwide, as with smallpox.
How Long Does Immunity Last After Getting a Vaccine?
A few vaccines, like the two for measles or the series for hepatitis
B, may make you immune for your entire life. Others, like tetanus, last for many years
but require periodic shots (boosters) for continued protection against the disease.
The whooping cough (pertussis) vaccine also does not give lifelong
immunity, and that may be one reason why outbreaks still happen. Whooping cough isn't
a serious problem for older kids and adults, but it can be for infants and young children.
Because of this, teens and adults now receive a pertussis booster along with the tetanus
and diphtheria booster (Tdap) — an important step in controlling this infection,
particularly for pregnant women and other adults who will be around newborn babies.
It's important to keep a record of vaccinations so the doctor knows when your kids
are due for a booster. Also make sure your kids get the flu
vaccine each year. Having been immunized last year won't protect someone from
getting the flu this year because flu viruses constantly change. The vaccine is updated
each year to include the most current strains of the virus.
The flu vaccine reduces the average person's chances of catching the flu by up
to 80%. It can't prevent infection by all viruses that can cause flu-like symptoms,
though, so being immunized isn't a guarantee that someone won't get sick during flu
season. Still, even if someone who's gotten the vaccine has the flu, symptoms usually
will be fewer and milder.
How Are Vaccines Studied and Improved?
The FDA's Center for Biologics Evaluation and Research is the government agency
that regulates vaccines in the United States. Working with the CDC and the NIH, they
continuously research and monitor vaccine safety and effectiveness.
New vaccines are licensed only after thorough laboratory studies and clinical trials,
and safety monitoring continues even after a vaccine has been approved. There have
been — and will continue to be — improvements (such as those that have
already been made to the DTaP and polio vaccines, for example) that will minimize
potential side effects and ensure the best possible safety standards.
Where Can I Get Affordable Immunizations for My Child?
Clearly, vaccines are one of the best tools we have to keep kids healthy. But they
work best when everyone gets them. Vaccines are now required to be covered by health
insurance plans with no charge to the patient. Some insurance plans only cover vaccines
when they are given by your doctor or at specific locations. So check with your insurance
company to make sure. You can also get inexpensive or free vaccines through many local
public health clinics and community health centers, and campaigns to vaccinate kids
often hold free vaccination days.
The U.S. government's Vaccines
for Children program covers Medicaid-eligible, uninsured Alaskan and Native American
populations, and some underinsured kids for routine immunizations up to 18 years of
age. The vaccines are provided by the government and administered in a doctor's office.
But the doctor's visit itself is not covered (unless the child has
insurance, including Medicaid). Some public health clinics may cover both the visit
and the immunizations.