The immunization debate: what's a parent to do? Childhood immunizations have come under some fire in recent years. Here's help separating the hype from the reality of what those shots do.

When our daughter Britt told us that Baby Zoe had gained almost three pounds her first month of life, we were thrilled. The weight gain was a positive sign that our new granddaughter, weighing just five pounds at birth, was healthy and growing. But when Britt added that she was afraid to give Zoe the recommended childhood immunizations, our elation turned to concern.

Many parents today are questioning the safety of childhood immunizations, wondering if the vaccines may cause more harm than good. Even with the knowledge that vaccines save lives, there are uncertainties about what the immunization may trigger in the child's body. While some fear causes us to seek answers, much of the fear of immunizations is based on misinformation, whether from news stories reporting a "possible" link between a childhood vaccine and illness or from Internet groups that are opposed to immunizations.

Even with opposition, immunizations are perhaps one of the greatest medical successes of the twentieth century, as they have virtually eliminated diseases that used to kill or harm thousands of children. Consider that before vaccines, each year polio paralyzed 10,000 children, rubella (German measles) caused birth defects and mental retardation in as many as 20,000 newborns, and pertussis (whooping cough) killed 8,000 children (most of whom were infants).

While these disease statistics are now history, we're not totally out of the woods yet. The bacteria and viruses that result in preventable disease or death are still alive and can be transmitted to those who are not protected by immunizations. Even if there are only a few cases of a vaccine-preventable disease in the world, that disease could spread like wildfire across the globe, harming or even killing millions if we stopped immunizing our children.

How Do Vaccines Work?

Using an inactivated (killed) agent or an attenuated (weakened) live organism, vaccines stimulate the immune system into reacting as if there were a real infection. The immune system then fights off the "infection" and remembers the organism, so if it enters the body in the future, the immune system can quickly fight it off.

Under perfect conditions vaccines work to protect us from disease. But vaccines are not 100 percent effective for reasons related to the individual person. In fact, it is estimated that childhood immunizations are about 85 to 95 percent effective in protecting the recipients against disease.

Dispelling the Myths

Let's look at some immunization misconceptions as addressed by experts at the Centers for Disease Control and Prevention in Atlanta, Georgia:

Myth: Diseases had already begun to disappear before vaccines were introduced, because of better hygiene and sanitation.

Truth: There is no question that improved sanitation and socioeconomic conditions have impacted diseases. Still, when assessing the disease charts through the years, you can see the peaks and valleys, with the real, permanent drop occurring when the wide use of vaccines started. This is particularly seen with the measles vaccine and Hib (Haemophilus influenza type b) vaccine. For instance, it is known that sanitation in the United States is not better now than it was in 1990, so it's hard to attribute the virtual disappearance of Hib disease to anything but the vaccine.

Also, in countries such as Japan, Sweden, and Great Britain, which allowed the immunization levels of pertussis vaccine to drop because of fear of the vaccine, the disease soared to epidemic proportions. The same happened in the Soviet Union, where there is a major epidemic of diphtheria because of low immunization rates for children and adults.

Myth: There are "hot lots" of vaccine that have been associated with more adverse events and deaths than others.

Truth: All vaccine manufacturing facilities and vaccine products are licensed by the United States Food and Drug Administration (FDA), and every vaccine lot is safety tested by the manufacturer. If there was one problem, the FDA would recall a lot of vaccine immediately.

Myth: Vaccines cause many harmful side effects, illnesses, and even death.

Truth: You need to consider the alternative when you weigh the risk and benefits of immunization. Consider what smallpox, polio, or any of the other vaccine-preventable diseases could do to you or your child. Vaccines seem incredibly safe compared to these potentially deadly illnesses.

Adverse side effects from vaccines may include a sore arm or slight fever, but major illness from a vaccine is rare. In this case the benefits of disease prevention far outweigh the risk of possible side effects.

Myth: Vaccine-preventable diseases have been virtually eliminated from the Unites States.

Truth: While the United States has low levels of vaccine-preventable diseases, other countries in the world have outbreaks and even epidemics. In fact, children are commonly paralyzed by polio in India and killed by diphtheria in Russia. Consider one traveler bringing this disease back to the United States and how many people would be harmed if there were no vaccinations!

Myth: Giving a child multiple vaccinations at the same time for different diseases increases the risk of harmful side effects and can overload the immune system.

Truth: Children are exposed to a multitude of foreign antigens (substances) each day with the food they eat or even when they get a common cold. The goal is to immunize children as young as possible to give protection against the diseases in the early, vulnerable months of their lives. It has not been proved that giving young children multiple doses or a combination of vaccines will in any way compromise their health.

The Bottom Line

The bottom line is that we get immunized to protect ourselves, but we must also make sure we have the recommended vaccines to protect those around us. Talk to your doctor to make sure you and your family members are current on all recommended immunizations.

Vaccine-preventable Diseases

Diphtheria--a respiratory infection caused by bacteria that is transmitted the same way as a cold. Symptoms include sore throat and low-grade fever.

Haemophilus influenza type b (Hib)--a severe bacterial infection that causes fever and chills. This infection is the leading cause of bacterial meningitis, a serious condition that can result in mental retardation.

Hepatitis A--an inflammation of the liver caused by the hepatitis A virus. This form of hepatitis is spread through food, water, and feces, especially in highly unsanitary conditions. It can also be spread by the fecal-oral route. It should be treated immediately.

Hepatitis B--a virus that results in liver damage as the body responds to the virus. Hepatitis B is spread or acquired through exposure to infected blood or body fluids.

Influenza (flu)--a highly infectious viral illness that results in fever, chills, cough, nasal congestion, body aches, and headache and can lead to pneumonia. (Influenza vaccine is an annual vaccine that is specially targeted to the year's flu strains.)

Lyme disease--a bacterial infection spread by certain types of ticks, with symptoms of rash, fever, tiredness, headaches, and muscle or joint pain. (This vaccine is not part of the recommended childhood immunizations.)

Measles--a highly contagious viral infection spread by coughing and sneezing, with cold symptoms, fever, and a red, itchy rash over the entire body.

Mumps--a viral disease that causes swelling of the parotid glands (and, secondarily, other salivary glands) next to the jaw, fever, headache, muscle ache, and sore throat. Mumps is more serious for adolescents and pregnant women.

Pneumococcus--a type of bacteria that causes pneumococcal pneumonia, with symptoms of high fever, cough, and stabbing chest pains. Pneumococcus can also cause bacteremia and meningitis.

Pertussis (whooping cough)--a respiratory tract infection that is transmitted like a cold and causes months of chronic coughing.

Polio (poliomyelitis)--a viral infection of the inflammation of gray matter of the spinal cord that causes fever, nausea, sore throat, headaches, stiffness, and stomachaches. Polio targets the central nervous system, and can result in weakness or paralysis of the muscle groups.

Rubella (German measles)--a respiratory infection that is spread by coughing and sneezing and starts with an itchy facial rash and fever. Rubella can cause miscarriage and birth defects if acquired by pregnant women.

Tetanus--a bacterial disease of the nervous system that enters the body through a break in the skin and causes lockjaw, stiffness in the neck and abdomen, and difficulty swallowing.

Varicella (chicken pox)--an infection caused by a herpes virus that is spread by coughing and sneezing and results in skin lesions and rash.

Immunizations: Not for Kids Only

Check with your doctor to make sure you are current with the following recommended immunizations:

* measles

* mumps

* rubella

* tetanus

* diphtheria

* chicken pox

* pneumococcal disease

* hepatitis A and B

Expert Advice

Kimberly Thompson, assistant professor of Risk Analysis and Decision Science at Harvard School of Public Health, is a risk analyst who focuses primarily on kids' health risks. As a scientist and a parent Thompson believes that the health benefits conveyed by vaccination far outweigh the risks posed by the vaccines themselves.

Q. In your perception, why are some parents fearful of getting immunizations for their children?

A. Some parents fear getting immunizations for their children because they don't like to see their child cry after being poked by a needle. Or they might see each injection as a risk--a chance that something could go wrong and that their child might be one of the unlikely few who experience serious side effects. Most parents cannot easily see the enormous benefits that vaccines provide: the time not spent paralyzed from polio, the deaths avoided from bacterial meningitis, or the hours not spent tending to a child at home or in a hospital with an infectious disease that was once common.

Q. Are the parents' fears warranted? Are there medical studies to support these fears?

A. Since the process of vaccination began with the technique of variolation [inoculation with smallpox] in Colonial times, the risks and fears have also been a part of parenting. Medical studies document side effects that follow vaccination in much the same way that they document the increased risks from the diseases in unvaccinated populations. For example, until a few years ago, when the U.S. switched from the oral polio virus vaccine to the inactivated polio virus vaccine, every year approximately eight to 10 American children would develop cases of vaccine-associated paralytic polio. That's a very small number compared to the thousands of children who would be expected to get polio if the wild polio virus still existed in the U.S. and children were not vaccinated. With the use of the inactivated polio virus vaccine, the vaccine-associated paralytic polio cases disappeared, and now only milder side effects are of concern. Unfortunately, this is not possible with all vaccines, and some generally small risks will remain along with the large benefits.

Q. What are the possible consequences of failure to immunize?

A. Currently parents face two major consequences of failing to immunize their children. First, the child remains susceptible to the infectious disease, and this could mean that the child may get, and even die from, an otherwise avoidable disease. While background rates of many diseases remain low with the current success of immunization programs, some of the diseases could again become epidemics if many parents fail to immunize. Second, in many school districts failing to immunize could mean that your child cannot enter school. These rules exist to protect children in schools and to encourage vaccination.

Q. How does the new threat of bioterrorism impact the need to get immunized?

A. The new threat of bioterrorism should serve to heighten people's awareness of the potential impacts of infectious disease. Still, it is unlikely to change immunization schedules, since we do not currently have vaccines for bioterrorism agents that are approved by the Food and Drug Administration and are readily available. Some bioterrorism agents may first lead to flulike symptoms, prompting your physician to suggest a flu shot. Talk to your physician about this, and at the same time make sure that your immunizations are current.

Debra Fulghum Bruce is a writer on health issues from Atlanta, Georgia.