Chapter One
The Story of Vaccines Perhaps you've seen the bumper stickers that say "question Authority." Well, that's what's happening today with the increasing number of parents who are questioning the safety, effectiveness, and even the necessity of the vaccines being given to their children and required by state law. Parents-and perhaps you are one of them-are questioning health-care providers, state health officials, and each other about immunizations. They are forming and joining action groups so they can learn more, and do more, about vaccine policies in the United States.
Next to the Question Authority sticker should be another one that says "Knowledge Is Power." It's not a good idea to question authority when you don't know what you're talking about, because it won't help you accomplish your goals. And when the goals are safe health care and a healthy life for your children, the stakes are too high for you to miss the mark.
This chapter introduces you to the information you'll need to help you understand the world of vaccines and how they can affect you and your children. It explains what vaccines are, types of vaccines, how they are developed, and how they affect the immune system. You will also learn the answer to the question "Do I have to vaccinate my child?" as well as how to use the rest of this book to answer this question for each of the vaccines required by law and for those that are not.
TEN VACCINES ... AND COUNTING
Today's parents are primarily concerned about the ten vaccines now recommended by the federal government and mandated by the states. That is not to say there is no controversy surrounding other vaccines, like those for influenza, Lyme disease, and hepatitis A. And there are dozens of other vaccines on the horizon, a future you may need to consider if you are a parent or grandparent. These other vaccines are covered in chapters 12 and 13. For now, however, here are the ten that are mandatory in most states:
Hepatitis B-the first vaccine children are typically given
DTaP-diphtheria, tetanus, pertussis (whooping cough), which is the newer form of the DPT (DTP) vaccine
Hib-Haemophilus influenzae type B
Polio-the inactivated polio vaccine, or IPV, is the injected form of the polio vaccine, which as of January 1, 2000, was recommended over the oral polio vaccine (OPV)
MMR-measles, mumps, and rubella combination vaccine Varicella-chicken pox
WHAT IS A VACCINE?
A vaccine is a substance that attempts to protect people against disease. To do that, vaccines are made from the virus or other pathogen (germ) that causes the disease the vaccine is designed to fight. You might say a vaccine uses fire to fight fire: A little bit of the pathogen is specially prepared and usually injected into the body so it can help fight off any "wild," or naturally acquired, versions of the disease. The purpose of that fight is to develop immunity.
The body has a complex system, called the immune system, that has procedures for producing and maintaining immunity. We can avoid long explanations by saying that when you get, say, a cold or flu virus or a bacterial infection, your body responds by producing substances called antibodies, minute protein molecules that fight against (anti) the foreign bodies (the viruses, bacteria). When you recover from the illness, your body retains some of those antibodies so it is ready to fight off the infection should it appear again. This is called immunity.
The main purpose of a vaccine is to stimulate the formation of antibodies at a concentration high enough to stop the pathogen in its tracks, and thus prevent those who get the vaccine from getting the disease. As long as you maintain a certain concentration for a specific disease, you have immunity.
Immunization is no guarantee that your child or you will not get the disease. A small amount of the infectious agent can get past the antibodies and cause individuals to experience some mild symptoms, or occasionally even worse effects of the disease. (More on this topic in subsequent chapters.) However, in most cases, the vaccine prevents more serious symptoms from occurring. An up-to-date list of the vaccines recommended by the U.S. government and mandated by the states can be seen at or downloaded from www.aap.org/family/parents/immunize.htm. An in-depth explanation of each of these vaccines can be found in chapters 6 through 11 in the book. Included in these explanations is the Vaccine Information Statement, or VIS. A VIS is an information sheet, produced by the Centers for Disease Control and Prevention, which informs vaccine recipients or their parents or legal guardians about the benefits and risks of the vaccine. Doctors are required by law to distribute a VIS for all mandated childhood vaccines.
AN INFANT'S IMMUNE SYSTEM
Infants come into the world with antibodies they have gotten from their mother through the placenta. Infants who are breastfed continue to receive many important antibodies in the colostrum (the thick, yellowish premilk that is secreted during the first few days after a woman gives birth) and breast milk. Commercial infant formulas, although inferior to mother's milk, also provide essential nutrients for infants' health.
During the first year of life, the immunity an infant gets from its mother at birth wears off. To help boost the fading ability to fight certain diseases, vaccines are given. The idea behind vaccines is to provide just enough of the disease-causing substance to trick the body into producing antibodies against it. Once the antibodies are produced, they stay around, protecting the child against the disease they were designed to fight. Some vaccines provide this protection for life after just one or two shots; others require additional "boosts" of immunity.
The problem many doctors and parents have with vaccines given during the first few months of life is that an infant's immune system cannot adequately respond to a vaccine until he or she is four to six months old. That's not to say that vaccines should not be given to children. They do save lives. However, I believe we need to look not only at the timing of these vaccinations-when they are given and how many are given at one time-but also at the ingredients in them and the dangers they may cause.
WANTED: DEAD OR ALIVE?
Vaccines have traditionally come in two basic forms: dead (inactivated or killed) or live. The vast majority of both forms are delivered one of two ways: via injection under the skin (subcutaneous) or into the muscle (intramuscular). (Polio and typhoid vaccines are also available in oral form.) In some cases, both live and killed vaccines are available to treat the same disease.
A third type of vaccine, the recombinant DNA vaccine, is the product of genetic engineering. It is the newest form but there are remaining questions about safety and efficacy.
Live Vaccines
Live vaccines are made in a laboratory from the living organism (usually a virus) that causes the disease. Live vaccines are attenuated, or weakened, so they will cause the body's immune system to generate an immune response without (hopefully) causing the disease. Some people, however, do respond to a vaccination by developing symptoms of the disease, although in most cases they are mild. Examples of live attenuated virus include polio (oral), measles, mumps, chicken pox, rubella, and yellow fever. Live bacterial vaccines include one for typhoid fever and Bacillus-Calmette-Guerin (BCG) vaccine, which is used for tuberculosis.
Some experts claim that the immune system responds to live, attenuated vaccines the same way it does to a natural infection; others disagree. In fact, even proponents of live vaccines agree that live vaccines can cause a mild version of the disease they are designed to prevent. People who question the wisdom of giving live vaccines, especially to infants and young children, say these vaccines may have much more serious consequences, pointing to the correlation with autism and autoimmune diseases.
Killed Vaccines
A killed, or inactivated, vaccine consists of all or part of the disease-causing organism that has been killed or rendered inactive. Unlike live vaccines, killed vaccines cannot reproduce, so they are not able to cause the disease they are designed to prevent. They trigger a weaker response by the immune system than do live vaccines. They also tend to be safer than live vaccines for people who have a weakened immune system, for pregnant women, and for children younger than one year.
Most killed vaccines are protein-based, like the bacteria they mimic. Some of these bacteria are coated with sugars called polysaccharides. When scientists tried to develop vaccines for sugar-coated bacteria, they found that pure polysaccharide vaccines didn't work well in infants. But when they joined (conjugated) the polysaccharide to a protein, the vaccines were much more effective for infants and young children.
Inactivated vaccines are used for the following diseases: cholera, hepatitis A, hepatitis B, influenza, Lyme disease, plague, pertussis (whooping cough), polio (injected), rabies, and typhoid.
Another type of inactivated vaccine are toxoids, which are made by inactivating the toxins (poisons) produced by bacteria and viruses. The vaccines against diphtheria and tetanus are toxoids.
Recombinant DNA Vaccines
Another type of vaccine is a recombinant DNA (genetically engineered) vaccine. The hepatitis B vaccine is one example. Rather than using the entire organism, recombinant DNA vaccines are made by taking specific genes from the infectious agent (for example, virus, bacteria) and adding them to the vaccine culture. For example, hepatitis B vaccine is made by inserting a portion of the hepatitis B virus gene into baker's yeast, the culture in which this vaccine is produced.
Experts say recombinant DNA vaccines are more effective and safer than other types of vaccines because they don't contain the entire infectious agent and thus cannot cause an actual infection. However, the greatest concern about recombinant DNA vaccines is that they may cause the immune system to produce antibodies, which in turn attack parts of the body and cause health problems. Much is still not known about the effects of recombinant DNA vaccines.
ONE SHOT, TWO SHOTS, THREE SHOTS, FOUR?
It would be nice if we could protect children against all threats of childhood diseases, such as chicken pox, measles, diphtheria, whooping cough, and polio, in one strategically administered-and completely safe-shot or pill. Unfortunately, that is not the case. In fact, children receive about thirty-three doses of ten vaccinations by the age of five years. Not only do children need a separate vaccine for most diseases (hepatitis B, polio, Hib, and chicken pox are single vaccines; DTaP and MMR are multiple), they also need more than one dose of each vaccine, except for chicken pox if given to a baby (older children need two). The one or more additional doses of a vaccine given to help ensure the protection provided by the original dose(s) are called boosters. Booster doses are given a few months or sometimes years after the original dose. For example, the first three DTaP shots are the original doses given to establish immunity. The next two shots at twelve to eighteen months and at four to six years are boosters, as is the recommended Td (a DTaP shot without pertussis) shot at eleven to twelve years and every ten years thereafter.
Are Boosters Necessary?
To determine whether children need a booster, doctors can check their titers-the measurement of the amount or concentration of a substance in a solution. In the case of vaccines, it refers to the amount of antibodies present in a patient's blood and serum. If a person's antibody titer is high enough to make them immune to specific diseases, they may not need a booster. Unfortunately, doctors don't usually check a person's titers before giving a booster. If the practice of checking titers were put into place, we would probably be able to eliminate some of the boosters now being given to our children, and thus reduce the risk of adverse effects. Parents can consider asking that titers be checked before a booster is given.
WHERE IT BEGAN: A BRIEF HISTORY OF VACCINES
Vaccines are not a new idea, although the early forms would not be popular in today's world. One of the first recorded attempts at vaccinelike treatments occurred sometime during the seventh century when a group of Buddhists decided they could become immune to the effects of snake venom by drinking the foul substance. In sixteenth-century China, writings describe how people were inoculated against smallpox by placing the powdered scabs from infected children into the noses of healthy children. These people had the right idea: They realized they could help prevent a disease or condition by exposing themselves to a form of the substance that caused it, but they didn't fully understand what they were doing at the time.
A more scientific approach was used in the late eighteenth century by Edward Jenner, who discovered that inoculating people with the animal disease cowpox made people immune to the deadly human disease smallpox. This was an interesting concept, and fortunately for Jenner it helped save lives, but the use of an animal disease to treat humans also presented the possibility that other diseases could be introduced along with the intended virus. Another approach was needed.
Between the time Jenner published his work in 1798 and Louis Pasteur developed the first rabies vaccine for humans in 1885, several scientists, including Pasteur, were investigating this problem. During that time, Pasteur enhanced the concept of attenuation, which is the use of a weakened form of a virus to provide immunity. Pasteur found that a weakened form of chicken cholera (an attenuated form) was highly effective in preventing the disease. Attenuated vaccines are widely used today.
Protests against the use of vaccines are nothing new. When Pasteur introduced his rabies vaccine for humans in 1885, both doctors and the public rallied against its use. At the turn of the century, British troops fighting in the Boer War in South Africa strongly protested being inoculated against the serious disease typhoid.
Many exciting events and discoveries occurred in the world of vaccines in the decades that followed.
Continues...
Excerpted from What Your Doctor May Not Tell You About Children's Vaccinations by Stephanie Cave Copyright © 2001 by Stephanie Cave, M.D.. Excerpted by permission.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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