Vaccinations for Children, Why and When
None of us wants to see our children get sick. If we could, we would protect
them from any illness, no matter how small - even the sniffles.
Now suppose you could make your child safe from some of the most deadly
diseases in history....And suppose that at the same time you could also help
protect your neighbors' children and other children around the country from the
same diseases....And finally, suppose you could actually help to rid the world
of some of these diseases that have been crippling and killing children for
Vaccines are an amazing success story.
- Up through the early 1920's, diphtheria was one of the most dreaded
childhood diseases in the United States, killing over 10,000 people every
year. We started vaccinating children against diphtheria in the 1930's and
40's, and the disease started disappearing. Today it is rare for a doctor
even to see a case of diphtheria, much less have a child die from it.
- In 1962, the year before measles vaccine was introduced, almost 500,000
cases of measles were reported in the U.S. Ten years after we started
vaccinating there were about 32,000 cases, and ten years after that there
were fewer than 2,000. In 1998 and 1999, only about 100 measles cases were
reported each year.
- Until the middle of the 20th Century, smallpox was one of the most
devastating diseases the world has ever known. Millions died from it every
year. In 1967, the World Health Organization declared war on smallpox with
an intensive, worldwide vaccination campaign. Twelve years later, smallpox
was wiped out - gone from the Earth forever.
- Parents in the 1950's were terrified as polio paralyzed children by the
thousands. Then we learned how to prevent polio using the Salk and Sabin
vaccines. Now the fight against polio is nearly won, and soon it will join
smallpox as nothing but a bad memory.
Before we discuss the 12 routine childhood vaccines and the diseases they can
prevent, let's take a brief look at what vaccines are and how they work. Then we
will answer some of the questions parents ask about childhood shots.
How Immunity Works
You get sick when your body is invaded by germs. When measles virus enters
your body it gives you measles. Whooping cough bacteria cause whooping cough.
And so on.
It is the job of your immune system to protect you from these germs. Here's
how it works:
- Germs enter your body and start to reproduce. Your immune system recognizes
these germs as invaders from outside your body and responds by making proteins
called antibodies. Antibodies have two jobs. The first is to help destroy the
germs that are making you sick. Because the germs have a head start, you will
already be sick by the time your immune system has produced enough antibodies to
destroy them. But by eliminating the attacking germs, antibodies help you to get
- Now the antibodies start doing their second job. They remain in your
bloodstream, guarding you against future infections. If the same germs ever try
to infect you again - even after many years - these antibodies will come to your
defense. Only now they can destroy the germs before they have a chance to make
you sick. This process is called immunity. It is why most people get diseases
like measles or chickenpox only once, even though they might be exposed many
times during their lifetime.
This is a very effective system for preventing disease. The only problem is
you have to get sick before you develop immunity.
How Vaccines Help
The idea behind vaccination is to give you immunity to a disease before it
has a chance to make you sick.
Vaccines are made from the same germs (or parts of them) that cause disease -
measles vaccine is made from measles virus, for instance, and Haemophilus
influenzae type B (Hib) vaccine is made from parts of the Hib bacteria. But the
germs in vaccines are either killed or weakened so they won't make you sick.
Then the vaccines containing these weakened or killed germs are introduced
into your body, usually by injection. Your immune system reacts to the vaccine
the same as it would if it were being invaded by the disease - by making
antibodies. The antibodies destroy the vaccine germs just as they would the
disease germs. Then they stay in your body, giving you immunity. If you are ever
exposed to the real disease, the antibodies will be there to protect you.
Immunizations help your child's immune system do its work. The child develops
protection against future infections, the same as if he or she had been exposed
to the natural disease. The good news is, with vaccines your child doesn't have
to get sick first to get that protection.