Why So Many Shots?
Vaccines are vital in protecting your baby from disease.
by Loraine M. Stern, MD
article found in american baby (magazine), February 2005

When I first started practicing medicine 35 years ago, I saw children with major, life-threatening diseases, such as bacterial meningitis, spend weeks in the hospital and sometimes suffer brain damage, deafness, or even death. But today, thanks to vaccines-the most effective health tool ever created-many once-common childhood illnesses have virtually been eliminated. The problem is that many parents these days have become complacent, believing that their child can no longer get diseases like polio, meningitis, or the measles. And many question the safety of vaccines, wondering whether they contain harmful ingredients that will cause their child to have a bad reaction, get a serious disease, or in some cases, become autistic.

Here are a few of the most common questions I hear-and the answers I give to parents.

How do vaccines work?
Babies are born with some antibodies (infection-fighting substances) in their bloodstream that were passed to them in the womb from their mother. But as those inherited antibodies decrease in the first year of life, a baby must then develop new antibodies and other infection-fighting substances. When he gets a cold or the flu, for instance, baby develops antibodies against the illness that protect him from getting the same virus as easily again. However, there are some diseases you wouldn't want your child to catch just so he can become resistant to them, because they have such serious consequences. That's where vaccines come in.

Vaccines teach a baby's immune system how to recognize and fight off specific infections. Most vaccines are made from an inactive form of a virus, though a few-such as the measles vaccine-are made from a weakened form of a live virus. These vaccines don't cause disease but can stimulate a baby's body to recognize it. When the offending germ tries to invade, the baby's immune system remembers it and bans it from her body.

Why get vaccinated for diseases no one ever gets?
Quite simply, if children stop getting their shots, these diseases can return.

More than 30 years ago, I often had one or two children in the hospital with a brain infection caused by Haemophilus influenzae type b (Hib). In those days, 10 percent of all children with the disease suffered brain damage, went deaf, or died. In 1985, however, the Hib vaccine was introduced, and since then I've seen no cases at all. In fact, Hib cases in the United States have dropped from an annual 20,000 to just a handful a year.

But even though children don't often suffer from infections such as Hib anymore, these illnesses continue to be a threat. Children still die of communicable diseases in areas of the world where immunization is not practiced or available. Sometimes, with the free flow of travel across nations, these diseases are "imported." For example, measles are usually brought into the United States when an unvaccinated child or adult visits an area that contains the disease and returns home. If he or she is still in the one- to twoweek incubation period, then there is no sign of infection and the virus is contagious to others.

When should my child get her shots?
Your child will receive a total of about 16 to 20 shots in the first two years of life, which will vaccinate her against 23 diseases. The first vaccine (hepatitis B) is sometimes given in the hospital or postponed until the 2-month wellbaby visit. Infants generally receive vaccines at 2, 4, and 6 months; 9, 12, 15, and 18 months; and at 2 years of age. In some areas with a high rate of hepatitis A, two doses of a vaccine are recommended at age 2 or 3. Children also get booster shots for the measles, mumps, rubella (MMR); diphtheria, tetanus, pertussis (DTP); and poliovirus vaccines before entering school.

Will so many shots harm my baby?
Not at all. When infants are born, they are moving from a sterile environment (the womb) to the outside world, which is teeming with microbes. Within hours of birth, babies house bacteria in their intestines, which they've picked up from breathing, sucking, and swallowing; in turn, their body manufactures antibodies to keep the bacteria from causing infection. Newborns and infants have the capacity to form millions of different protective antibodies, but vaccines don't use up that potential.

Is it ever preferable for my child to get the natural disease?
No. The diseases we vaccinate children against can have serious consequences. Many parents today have had chicken pox. They recovered uneventfully, perhaps sustaining a few scars from the pox. But some children don't pull through that easily. In some cases, chicken pox can make children susceptible to infection and cause pneumonia. Since the chicken pox vaccine was introduced in 1995, however, the number of hospitalizations has gone down by 70 percent and the death rate has declined.

Will the shots hurt my child?
In truth, some shots-like the the combined MMR vaccine-are more painful than others. Some pediatricians suggest giving an infant a dose of acetaminophen or ibuprofen after baby is weighed at the beginning of the visit. it takes at least 30 minutes for pain medicine to work. Even if the pain reliever doesn't kick in in time, it can help with the pain or slight fever (up to 101 degrees) that some babies experience afterward.

Will my child have any side effects from the vaccines?
Children sometimes experience a little redness or soreness or a lump at the vaccine site, but this generally goes away in a few days. Some infants will also be a bit sleepier than usual the next day. If your baby has a fever of about 101 degrees or seems uncomfortable within the first 24 hours, offer a pain-and-fever reducer like acetaminophen or ibuprofen.

If your child has a history of serious allergies, particularly to eggs, gelatin, or certain antibiotics, such as neomycin, streptomycin, or polymixin, tell your pediatrician before your child is vaccinated. There may be trace amounts of these elements in certain vaccines. In some cases, children need to be immunized by a pediatric allergist, who can safely monitor the child's reaction.

Fortunately, true allergic reactions are rare, and most occur within minutes to hours after a shot has been given. If your child develops hives, itching, swollen lips, or has difficulty breathing, take him to an emergency room at once, or call 911. Also, make sure to alert your pediatrician if this happens.

There's so much scary information about vaccines on the Internet. How do I know what's true?
I suggest that you consider the source before you believe a thing Organizations like the American Academy of Pediatrics (aap.org) and the Centers for Disease Control and Prevention (CDC) (cdc.gov) offer reliable scientific data. Be skeptical of information from parent groups, chat rooms, or alternative publications, especially stories of a personal experience. Discuss any negative information that you uncover with your pediatrician.

Although vaccination is about the safest medical procedure around, the CDC and the FDA are constantly monitoring the safety of vaccines, and manufacturers are always trying to improve them. I remember the old DTP shot, for example, which often caused high fevers and other side effects in children. The newer acellular vaccine, now on the market for about ten years, is made without some of the unnecessary ingredients of the old one and causes far fewer and less severe reactions.

Finally, I'd caution parents not to obsess about the "dangers" of vaccines. For example, in the more than 70 million doses of the MMR vaccine that have been given in the United States, only 11 cases of serious reactions have been reported. On the other hand, if children were to get the measles infection (a disease the MMR vaccine protects against), 1 in 20 would come down with pneumonia, 1 in 800 would have a severe brain inflammation, and some would have permanent brain damage or die. That story in itself should make a compelling argument for vaccines.

Do vaccines cause autism?
Some people believe that vaccines-or, more specifically, thimerosal, a mercury compound that was once present in trace amounts in vaccines but has since been eliminated-can cause autism. It's becoming clear that autism is a genetic disorder, which may or may not be triggered by other components such as environmental factors. The idea that vaccines can cause autism has never been proved in large studies, but many parents today are still not convinced.

As a matter of fact, two recent studies showed the opposite to be true. A study from the University of Bristol in England, followed some 13,000 children for six to seven years, while a study from the Communicable Disease Surveillance Center, in London, reviewed the medical history of 100,000 children born between 1988 and 1997. In both studies, children were given vaccines that contained thimerosal. The results? Children who had a higher rate of exposure to thimerosal had a lower incidence of autism, developmental delay, hyperactivity, and conduct disorders than those who had less exposure to the compound. Though the media debate is far from over, these studies-plus the many that have preceded them-should shed light on the fact that thimerosal is not harmful to children.


Loraine M. Stern, MD, is a clinical professor of pediatrics at the University of California, Los Angeles, and a practicing pediatrician.