Should parents have the right to refuse standard childhood vaccinations

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Should parents have the right to refuse standard childhood vaccinations?

Viewpoint: Yes, a properly run voluntary system could produce higher vaccination rates while also protecting parents' rights.

Viewpoint: No, mandatory vaccinations have greatly reduced the incidence of many diseases and should be maintained.

Controversies over vaccination are not a new phenomenon. Learned debates about the safety, efficacy, morality, and even theological status of vaccination have raged since eighteenth-century physicians began to investigate ancient folk practices meant to minimize the danger of smallpox. Analyzing the risks and benefits of immunization, however, requires sophisticated statistical approaches to general mortality rates, case fatality rates for specific diseases, and studies of the safety and efficacy of various vaccines.

Until the nineteenth century, reported mortality rates were generally very crude estimates, but attempts to provide more accurate measurements of vital statistics through the analysis of the weekly "Bills of Mortality" began in the seventeenth century. During this time period, smallpox was so common that distinguished physicians considered it part of the normal human maturation process. Many eighteenth-century physicians were influenced by Enlightenment philosophy, which inspired the search for rational systems of medicine, practical means of preventing disease, improving the human condition, and disseminating the new learning to the greatest number of people possible. Johann Peter Frank's System of Complete Medical Police provides a classic example of the goals and ideals, as well as the sometimes authoritarian methods, employed in public health medicine. Of course harsh, even draconian public health measures can be traced back to the Middle Ages, as the authorities struggled to contain bubonic plague.

One of the most significant medical achievements of the eighteenth century was recognition of the possibility of preventing epidemic smallpox by inoculation (the use of material from smallpox postules) and vaccination (the use of material originally derived from cowpox postules). Smallpox probably accounted for about 10% of all deaths in seventeenth-century London. About 30% of all children in England died of smallpox before reaching their third birthday.

Smallpox left most of its victims with ugly pitted scars, but blindness, deafness, and death might also occur. Peasants in many parts of Europe attempted to protect their children by deliberately exposing them to a person with a mild case. Some folk healers took pus from smallpox pustules and inserted it into a cut or scratch on the skin of a healthy individual. In China, some practitioners had patients inhale a powder made from the crusts of smallpox scabs. Although such practices were dangerous, patients who survived enjoyed immunity to the naturally acquired infection. When inquisitive individuals like Mary Wortley Montagu and Cotton Matherbrought smallpox inoculation to the attention of physicians, clergymen and physicians denounced this "unnatural" practice. Some theologians argued that inoculation was a dangerous, sinful affront to God, who used disease as a test of faith and a punishment for immorality.

When smallpox struck Boston in 1721, Mather and Dr. Zabdiel Boylston initiated a test of inoculation, but their efforts generated great fear and hostility. One critic threw a bomb through Mather's window along with a note that read, "COTTON MATHER, You Dog, Dam you, I'll inoculate you with this, with a Pox to you." After performing more than 200 inoculations, Boylston concluded it was "the most beneficial and successful" medical innovation ever discovered. In contrast, Dr. William Douglass, Boston's best-educated physician, argued that it was a sin to transmit a disease by artificial means in order to infect people who might have escaped the naturally acquired disease. Boylston and Mather later presented statistical evidence to show that the mortality rate for naturally acquired smallpox during the epidemic had been significantly less than that for the inoculated group.

Inoculation had important ramifications for medical practitioners and public health officials, ramifications that are still part of the modern debate about compulsory vaccinations. As Benjamin Franklin explained, weighing the risks and benefits of inoculation became an awesome responsibility for parents. In 1736 Franklin printed a notice in the Pennsylvania Gazette denying rumors that his son Francis had died of inoculated smallpox. The child had acquired natural smallpox before he could be inoculated. Knowing that some parents refused to inoculate their children because of fear that "they should never forgive themselves if a child died under it," he urged them to consider that "the regret may be the same either way, and that, therefore, the safer should be chosen."

By the second half of the eighteenth century, inoculation was a generally accepted medical practice. Inoculation paved the way for the rapid acceptance of vaccination, the method introduced by Edward Jenner in the 1790s. While practicing medicine in the English countryside, Jenner became intrigued by local folk beliefs about smallpox and cowpox. Although cowpox usually caused only minor discomfort, it provided immunity against smallpox. Critics warned that transmitting disease from a "brute creature" to human beings was a loathsome, dangerous, and immoral act. However, despite considerable skepticism and debate, Jennerian vaccination was rapidly adopted throughout Europe and the Americas. As early as 1806, Thomas Jefferson predicted that thanks to Jenner's discovery smallpox would eventually be eradicated.

Some opponents of vaccination insisted that any interference with "nature" or the "will of God" was immoral and that deliberately introducing disease matter into a healthy person was an abomination. Others warned that even if inoculations appeared to be beneficial, the risks outweighed the benefits. Other critics objected to the enactment of laws that infringed on personal liberty. On the other hand, Johann Peter Frank said that vaccination was "the greatest and most important discovery ever made for Medical Police." Frank predicted that if all states adopted compulsory vaccination, smallpox would soon disappear. Vaccination was made compulsory in the United Kingdom in the 1850s, but the vaccination laws were not generally enforced until the 1870s. Despite a dramatic reduction in the death rate from smallpox, critics continued to denounce the statutes as "a crime against liberty."

In the 1910s epidemiologists were still complaining that the United States was "the least vaccinated of any civilized country." Many states passed laws prohibiting compulsory vaccination. After World War II compulsory vaccination laws were extended and more vigorously enforced. The risk of contracting smallpox within the United States became so small that in 1971 the Public Health Service recommended ending routine vaccination. Medical statistics demonstrated the risks of the vaccine itself: 6 to 8 children died each year from vaccination-related complications. Unfortunately, with the global eradication of smallpox and the end of smallpox vaccination, the threat that the disease could be used as a weapon by bioterrorists escalated. According to officials at the Centers for Disease Control and Prevention, the appearance of smallpox anywhere in the world would have to be regarded as a global public health threat.

In describing the 10-year campaign for the eradication of smallpox led by the World Health Organization, Donald A. Henderson proposed the next logical step: what had been learned in the smallpox campaign should form the basis of global immunization programs for controlling diphtheria, whooping cough, tetanus, measles, poliomyelitis, and tuberculosis. However, as demonstrated by the 1976 campaign for mass immunization against an expected swine flu pandemic, reports of any adverse effects from a vaccine can quickly lead to widespread fears, criticism of public health authorities, and skepticism about the relative risks and benefits of all vaccines. Compulsory childhood vaccination programs remain particularly controversial, as shown by the following essays, but in an age of extensive and rapid movement of people, the existence of infectious epidemic diseases anywhere in the world is a threat to people everywhere.

—LOIS N. MAGNER

Viewpoint: Yes, a properly run voluntary system could produce higher vaccination rates while also protecting parents' rights.

Public concern about vaccination has reached an alarming stage. A series of congressional hearings have brought into public focus not only the potential undesirable side effects of vaccines, but also raised issues of our century-old policy of compulsory vaccination. Blue ribbon panels of the National Academy of Sciences' Institute of Medicine have for years been examining alleged links of vaccinations to a rising incidence of serious adverse events and potential links to disease. Many citizen and health care provider groups have called for an end to requiring infant vaccinations for entry into schools, infant day care, and participation in childhood activity programs. Some groups advocate an antivaccine position not only on religious or conscientious philosophical objection, but because they attribute to vaccines the cause of many growing childhood and adult maladies.

How has the trust in immunization programs, one of the marvels of modern medical advances, come to be so diminished? Why should parents be forced by law to have their infants vaccinated? Why have the potential harms of vaccines not been made better known? Why cannot parents make the decision about vaccinations for their children, as is common in other western societies?

Vaccines are an effective method of stopping epidemics and preventing disease. But they are not entirely safe—nor, unfortunately, are they always 100% effective. They are not for every infant. Nor are they consistent with deeply held convictions of many in our society. Our laws have consistently recognized an exception on religious and philosophical grounds as well as on medical grounds, when allergic reaction or poor health compromises the immature immune system.

However, those who would decline to have their children vaccinated are often intimidated by their physicians and humiliated or ostracized by school authorities and administrators of childhood and youth programs. Sometimes the threats may include legal sanctions and penalties. Many parents go so far as to isolate themselves from mainstream medical care and community involvement to avoid being coerced to immunize their children. The approach of compulsory vaccination is fraying. Confidence in the protection against disease provided by vaccination is ebbing. Many families not only decide to forego immunization; they are choosing to distance themselves from the well established benefits of modern medicine altogether.

Reasons for the Current Debate

A major reason for the current public debate over the value of childhood vaccination lies in the type of decision-making behind it. When common childhood epidemics ravaged the population, there was little time or opportunity to take into account the dissident views of the portions of society that balked at vaccination. In 1905 and again in 1922, the U.S. Supreme Court decided that the government could require vaccination to prevent the spread of contagious diseases that threatened death, disability, and serious illness not only to individuals contracting the disease but to the population as a whole. Compulsory vaccination was the only way to control outbreaks of lethal disease.

Surely, fresh in the minds of all at the time of the 1922 Supreme Court decision was the experience of the deadly influenza epidemics after World War I, which took over 40 million lives worldwide. Although no influenza vaccine was dreamed of at the time, the clear model for vaccinating the population was the way we had countered the dreaded smallpox virus that had so often devastated populations around the world. As Daniel A. Salmon and Andrew W. Siegel point out in their article in July-August 2001 number of Public Health Reports, "Many of the [state] laws were written with specific reference to smallpox and later amended to include other VPDs [vaccine preventable diseases]." Drastic measures to prevent enormous numbers of deaths were imperative.

Even today, after smallpox has been eradicated from the world, the threat of unleashing a bioterrorist attack of this disease looms as a dreaded potential in our nation, which, ironically, ceased requiring the vaccination by the 1980s.

What made sense in the past when so-called invisible and unknown "killers" were unleashed in a community, seems now to be unwarranted. As regards smallpox, for example, now that we know that vaccination against smallpox may, in fact, kill, disable, and disfigure some small percentage of those who receive it, we hesitate to encourage or recommend it except for those whose duties would place them at immediate peril of the disease. But other diseases for which we now have vaccines do not pose such fearsome threats to the population.

In part, this is owing to the success of vaccines. "Before the vaccines were introduced," reads a 2001 report in the respected Consumer Reports magazine, "the toll of 10 of these vaccine-preventable diseases—diphtheria, measles, mumps, pertussis, polio, rubella (German measles), tetanus, hepatitis B, pneumococcus, and HiB [childhood influenza]—was nearly 2 million reported cases per year. Even the 'mildest' vaccine preventable disease, chicken pox, claimed 100 lives each year."

So our standard of evaluating costs vs. benefits is different. We were ready and willing to accept compulsory vaccination when it could save thousands of lives and prevent deafness, blindness, and brain disorders. But now, as some of the unavoidable adverse effects of vaccines emerge, we do not have the background of immediate danger against which to measure the response of society. Preventing 1,000 deaths by vaccination is clearly desirable. But what if there are 10 vaccine-related injuries in the process? Is the vaccine worth the risk? For those who must protect the public health, the answer is unclear.

Parents' Rights

If we try to incorporate the values our society holds important into the equation, cost-effectiveness is no longer the sole yardstick. In addition to the now-well-established risk to the individual child, what of the parents' rights to decide about the well being of the child? At present, parents are confronted with little or no choice in whether their children are subjected to mass vaccination. A program of no-fault compensation has been established by the federal government to cover injuries related to vaccine administration, but no amount of money can compensate for loss of the child or permanent physical and mental disability.

The risks a parent of a very sick child may be willing to accept to treat or cure the child are judged in the context of the desperate hope to save the child's life. But vaccines are administered to healthy children, to infants who are only a few months old. These children are not ill, though they face a possibility of illness from a vaccine-preventable disease. Consequently, some parents would rather take their chances with the disease, particularly today when so many diseases seem unlikely to occur. Mandatory vaccinations limit parents' freedom to take care of their children as they see fit.

All states provide for medical exemptions for children with diseases like leukemia or allergic reactions or weakened immune systems, since officials know that vaccination carries a greater risk for such children. Medical exemptions must be verified by a physician's report. Laws in 48 states allow for parents to request exemptions on the grounds of religious belief, and in 17 states exemption can be based on philosophical or personal reasons. Some studies indicate that a growing number of parents exercise that option. However, this option comes at a cost, both to the child and to society as a whole.

The nonvaccinated children are at a much higher risk for getting the disease. Some claim that should nonvaccinated children become infected, they also pose a greater risk to others in the population. Accordingly, those pressing for compulsory vaccination argue that exemptions undermine the effort to curb disease and threaten the public health.

Some studies do reflect a trend of increased childhood diseases as parents opt for no vaccination. But the studies are limited in scope and the trends are hard to interpret. One anecdote illustrates what can occur when parents forego vaccination for their children. In Philadelphia in the 1990s, a resurgence of measles infected 1,600 children and killed nine. Officials tied the outbreak—perhaps unfairly—to the decision made by a single religious group to forego vaccinations for the children in their midst. As children inside the religious community became sick, they inevitably infected children in the city as a whole.

The group exercised its rights to refuse vaccination under Pennsylvania law. However, the reaction of public health officials in assigning blame to the group illustrates the pressure such advocacy puts on parents who have reservations about vaccines based on the spotty safety record and manufacturing lapses presented in congressional hearings and documented in scientific literature.

No doubt the medical and public health professions advocate vaccination for good reasons. It is their professional and informed judgment that leads them to that position. However, their zeal only serves to blind them to the well established rights of minorities in our society. There are very sound arguments for vaccination of children. With proper information and education, parents themselves can weigh the benefits to their children and the need to take precautions so that other members of the community are not placed at risk of contracting the diseases. But even deeply held religious beliefs may not be enough to excuse parents from responsibility for the deaths of innocent children. Many health professionals turn a deaf ear to legitimate rights and concerns of the public. The record, as established in congressional hearings, documents a persistent disregard of the concerns raised by citizens and their elected representatives.

Many of the concerns raised by anxious parents and parents of those whose children have been injured betray the overreaction to alleged but unsubstantiated claims. Adverse events go underreported, but seldom are they serious. The Immunization Safety Review Panel of the Institute of Medicine has reviewed and independently assessed most of the claims of major harms caused by vaccinations. Consistently, the Panel has not been able to find conclusive evidence that the harms are extensive or even linked to the vaccination. Of course, this is of little consolation to the parents of children with autism, epilepsy, learning disabilities, and multiple sclerosis.

Safety Problems and Quality Control Lapses

What makes those claims worrisome to parents is the clear evidence of safety and quality control lapses. Batches of vaccines are found to be "bad," though that does not always result in actual harms to the children. For decades a preservative in vaccines was a substance, thimerosal, containing mercury, which is a known toxin, particularly dangerous to pregnant and nursing mothers and very young children because it can impair cognitive development.

Polio vaccine has led to an almost complete eradication of the disease. In fact, from 1979 to 1999 the only cases of polio in the United States were caused by the oral polio vaccine, which contains the live virus. Over the 20 years, there were eight to nine cases of polio each year. Meanwhile, a safer vaccine, the killed-virus Salk vaccine, was developed. Public health officials, however, were slow to recommend that communities begin using the killed-virus vaccine rather than the live-virus one.

Until authorities demonstrate steps to restore public trust in the promise of vaccines, it is reasonable to suppose that parents may have serious misgivings about vaccinating their children. Fortunately, there are signs of improvement in the oversight of vaccine administration, in quality control, and in efforts to involve the citizenry more directly in decisions about vaccine policies. The misunderstanding and misinformation that have contributed to the lost of trust in vaccination programs would not have gained such a strong foothold had authorities been more responsive and forthcoming in dealing with the public. In the meantime, is it fair to expect parents to subject their children to vaccinations?

There is no major, imminent threat, such as smallpox, that as a practical matter leaves little room for choice. The history of vaccination laws illustrates the reasoning that was behind the need to protect the public from the havoc of epidemics. Vaccines may prevent illness, but medicine has improved sufficiently that many of the highly contagious vaccine-preventable diseases do not threaten the whole population. It is perhaps time to reexamine the policy of compulsory vaccination.

The Model of Great Britain

In Great Britain, for example, under a voluntary vaccination program, there are higher rates of immunization than in the U.S. under the compulsory program. In a recent report on vaccination, the core principle of voluntary childhood vaccination was reaffirmed. The public was informed that at the current rates of 90 to 95% voluntary vaccination, there was adequate protection for all.

It appears that public health authorities in the United States may have become complacent in their efforts to promote vaccination. As long as vaccination is compulsory, there is little need to inform and educate the public. A voluntary program in which public officials work hard to persuade private citizens to comply may yield a higher vaccination rate than a "mandatory" program in which there is little public advocacy.

Still, it will be argued, the need to protect other members of society from highly contagious diseases is undermined by a policy that allows for parental choice. However, this view substantially undervalues the individual's sense of civic and public responsibility. Decades of compulsory vaccination policy have deadened the awareness of individuals of their responsibilities and even of their own enlightened self-interest.

The underlying problem has been, as stated at the outset, a pattern of top-down decision-making based on circumstances that are no longer true. As recently as 1999, 15 state legislatures considered bills to reduce or eliminate requirements of vaccination for school entry. The public does not perceive immediate danger. Consequently, it uses another yardstick to assess the risks. Authorities have not been effective in articulating the value of vaccination because they have relied on the compulsory policy. A vaccine is developed, tested, and introduced. Its benefits are trumpeted, but its potential harms are not. The federal government has slowly come around to underwriting some or all of the costs for childhood vaccines for those at the poverty level, but the program is underfunded and too limited to be effective even among this group. Others see the expense of vaccination as a mandated way of increasing the profits of drug companies. Both groups see only the financial aspect and ask themselves why they should be forced to pay for something over which they have no say.

Other Considerations

There is a broader set of considerations that need to be factored into the overall cost to society. First, there is the consideration of the effects of the disease vs. the effects of immunization. A parent will be willing to take steps to spare the child sickness or death. All of us have a clear interest in avoiding epidemics and in the huge costs that are entailed in loss of work and in medical expenses, not to mention personal harm. When we understand that immunization cannot work magic, but can reduce or eliminate the unwanted effects of diseases without on average any great harm, we can accept the choice. For those unfortunate enough to incur harm, society has established a fund to compensate. Thus, there is a sense of fairness to the system, although it will never be entirely fair to the injured parties.

A second area of consideration is the cost of taking away the freedom of choice of parents in the matter of deciding about what is best for their children. It may be more efficient to bundle vaccinations in an assembly-line manner in a mass inoculation program, as occurred when the polio vaccine first became licensed. But the majority of childhood vaccines are administered now in the course of well-baby care by private physicians. Parents are presented with information about potential side effects, but they have no choice about whether to participate. This does little to help parents understand the public benefits of the program or their private responsibility for taking part in it.

Compulsory vaccination has served us well in the past. But it now thwarts many of the values we cherish. As the catastrophic epidemics of decades ago become a distant memory, Americans would be well served by the public health system transferring vaccination responsibility back to parents and working vigorously to educate parents about the need for routine vaccinations.

—CHARLES R. MACKAY

Viewpoint: No, mandatory vaccinations have greatly reduced the incidence of many diseases and should be maintained.

As the twentieth century dawned, America's children were in grave danger. Each year, hundreds of thousands were killed, deformed, or crippled by a villain that could be neither seen nor heard. Tiny germs and bacteria had the ability to invade cities, one person at a time, spreading like wildfire with a simple cough or sneeze. During the first half of the century, the numbers of children killed or injured at the hands of serious diseases were staggering. More than 15,000 children succumbed to diphtheria every year; 20,000 were born with severe mental or physical defects caused by rubella; and as many as 57,000 were crippled by polio. Smallpox alone decimated more than 300 million people—more than the total casualties from all wars combined—before it was eradicated in 1979.

Now, in the early years of the twenty-first century, American children face far less of a threat from disease. Smallpox has been eradicated, polio has been wiped out in much of the world, and the incidence of diphtheria, pertussis, and measles is very low. Millions of children who would not have lived to see their first birthday or who would have been wheelchair-bound for life are now thriving, thanks to what has been called the most beneficial health program in the world: immunization.

It seems inconceivable that anyone would choose not to take advantage of such a lifesaving technology, especially when vaccines have been proven safe and effective by the leading medical experts in the world. But many parents, because of religious or philosophical beliefs, misconceptions about vaccine safety, or concerns over personal freedom, are choosing not to vaccinate their children.

Americans are among the most privileged citizens in the world because we have been afforded freedom of choice. But that freedom is not absolute. Imagine if people were allowed to disobey traffic signals, or shoot guns whenever they felt like it? The result would be great harm inflicted on many innocent people. Similar to traffic and gun control laws, the federal government has upheld compulsory vaccination laws as reasonable to protect the general public. As the Supreme Court stated in 1905 in Jacobson v. Massachusetts, "in every well-ordered society … the rights of the individuals in respect of his liberty may … be subjected to such restraint, to be enforced by reasonable regulations as the safety of the general public may demand."

Dispelling the Myths about Vaccines

The single greatest concern parents have with regard to vaccines is over their safety. Some point to research linking vaccines with everything from sudden infant death syndrome (SIDS) to autism. Others say multiple vaccines can overwhelm a child's developing immune system or cause the illness they were designed to protect against. Experts counter that no vaccine is 100% effective, and just as with any medical treatment, there are risks, but the risks are minor when compared to the potential for death and disability from vaccine-preventable diseases.

Consider the statistics: For every 20 children infected with diphtheria, one will die. One in 200 children will die from pertussis, and one in 1,000 will die from measles. As many as 30% of people infected with tetanus will die. Compare that to vaccinations for these diseases, which have not been conclusively linked to a single death. When vaccines do cause side effects, they are usually minor. Some children will have redness or swelling around the injection site, or run a slight fever.

Vaccine-induced Disease

It's true that vaccines contain bacteria or viruses, but they have been either killed or weakened to confer immunity to the child without causing infection. As Louis Pasteur first discovered in the late 1800s, introducing these microbes is necessary to teach the body to regard diseases as foreign invaders. Normally, when the body senses invasion by a foreign body, for example a virus, it produces protein molecules called antibodies that move out into the bloodstream to attack and destroy the invaders. Once a person has been infected with an illness, the immune system learns to instantly recognize that particular virus as foreign, and will attack on sight, preventing future infection. Vaccines cause immunity by stimulating that same type of reaction without actually infecting the vaccinated person with the disease.

Vaccines and SIDS, Autism, and Diabetes

Studies linking the DTP (diptheria-tetanus-pertussis) vaccine with sudden infant death syndrome (SIDS), the MMR (measles-mumpsrubella) vaccine with autism, and the Hib (Haemophilus influenzae Type b—the bacteria responsible for one type of meningitis) vaccine with diabetes, have fueled incendiary media reports and ignited anger and fear among parents. With all three vaccines, links were determined because the conditions emerged shortly after children were vaccinated. Using this same logic, then, it would be safe to assume from a study of early morning car accidents that people who drank orange juice were more likely to be involved in an accident than those who drank lemonade. Of course, we know that's not the case. More people drink orange juice in the morning than lemonade, but the connection ends there.

In the case of the DTP vaccine, shots are administered when a child is between 2 and 6 months old, the age at which a child is at prime risk for developing SIDS. When the Institute of Medicine at the National Academy of Sciences reviewed a number of studies comparing immunized versus non-immunized children, they found that the number of SIDS cases in the two groups was nearly identical, and they concluded that "the evidence does not indicate a causal relation between [DTP] vaccine and SIDS."

Concerns arose about a link between the MMR vaccine and autism after a 1998 British study described 12 children who displayed behavioral problems shortly after receiving the vaccine. Experts say the study was faulty for several reasons, among them the small number of cases investigated and the lack of control children for comparison. Investigators studying the link subsequently have found no increase in autism cases since the MMR vaccine was introduced in 1971. Most scientists believe that autism originates in the developing fetus or shortly after a child is born. They say the MMR vaccine may actually confer a benefit by protecting the mother against rubella, one of the few proven causes of autism.

A handful of studies have also suggested that Hib, among other vaccines, increases a child's risk of developing type 1 diabetes. In patients with diabetes, the body either does not produce enough insulin (which is needed to convert sugars from foods into energy), or cannot use it effectively. One study, conducted in Finland, compared multiple doses with single doses of the Hib vaccine. It found that 205 children in the multiple vaccine group developed diabetes as compared to 185 in the single dose group. Scientists and public health officials have examined all related studies and have thus far been unable to find clear evidence that any vaccine increases a person's risk of developing diabetes.

Over the years, teams of researchers around the world have tried to assert a link between various vaccines and febrile seizures, neurological disorders, and inflammatory bowel disease. In each case, the leading doctors and medical experts in the United States thoroughly researched and disproved the connection.

As for the contention that multiple vaccines overwhelm a child's immune system, experts have found no evidence to support this theory. Children are not only able to tolerate multiple vaccines at once, but vaccines actually protect a child's immune system from attack by serious bacterial and viral infections. What's more, children are receiving far fewer antigens (substances that stimulate the body's immune response) in today's vaccines than they did 40 years ago. By age 2, each American child will have received 7 vaccines in a series of 20 shots, as compared to just 3 shots in the 1960s (diptheria-tetanus-pertussis, polio, and smallpox). The smallpox vaccine (which is no longer given) alone contained about 200 antigens; the combined antigens in the total number of vaccines recommended today add up to fewer than 130.

How Safe Are Vaccines?

Vaccines are among the safest forms of medicine ever developed, and the current vaccine supply in the United States is the safest on record, say health officials. Before any vaccine can be licensed by the Food and Drug Administration (FDA), it must go through extensive safety evaluations: first in the laboratory, then in animal trials, and finally in several phases of human trials, which may involve thousands of people. During the trials, vaccine manufacturers set the most effective dosage and look for any signs of adverse reactions. Even after licensing, manufacturers continue to monitor their vaccines for safety, submitting samples of each lot to the FDA for testing before the vaccine is released to the public.

In 1990 the Centers for Disease Control and Prevention (CDC) and the FDA established a database called the Vaccine Adverse Event Reporting System (VAERS). Health providers are required to report any adverse vaccine reactions to this system, and that information is combined with reports from vaccine manufacturers and the general public. Whenever an adverse reaction is reported into VAERS, the CDC and FDA act immediately, distributing safety alerts to doctors and the public, changing the wording on vaccine labels, and proposing changes to the vaccines themselves. For example, when concerns were raised in 1999 over thimerosal (a mercury-containing preservative used in vaccines since the 1930s), the Public Health Service and American Academy of Pediatrics called on health practitioners to avoid the use of these vaccines whenever possible, and urged manufacturers to remove the additive from all vaccines, which they did.

The Consequences of Ceasing to Vaccinate

Over the past four decades, several countries tried to decrease vaccinations, always with disastrous results. Great Britain, Japan, and Sweden cut back on pertussis vaccinations in the 1970s and 1980s out of concerns over the vaccine's safety. Soon after, a pertussis epidemic in Great Britain infected more than 100,000 people and killed 36. In Japan cases rose from 393 in 1974 (when the vaccine rate was about 80%) to 13,000 cases and 41 deaths in 1979 (when the vaccine rate fell to about 20%). In Sweden the annual incidence of pertussis cases among children ages 0 to 6 rose from 700 cases in 1981 to 3,000 in 1985.

Even the United States has suffered the results of reduced immunizations. Between 1989 and 1991, low coverage of MMR vaccinations among preschool children sparked a measles epidemic that infected 55,000 children and killed 120. Since then, coverage levels have risen to about 90%, and annual measles cases in the entire Western Hemisphere number fewer than 500 a year.

"If enough people refuse vaccination—and it can take a decline of only a few percentage points in the immunization rate—all children in the community are placed at greater risk," noted Dr. Bruce Gellin, executive director of the National Network for Immunization Information, in a statement released in 2000.

Modern vaccines are about 90 to 95% effective, which means that for every 20 children immunized, one or two may not become immune. Those one or two children are therefore vulnerable if they come into contact with the disease in school or at play. But if enough people in a community are vaccinated, it confers what is known as "herd immunity," protecting those at risk from disease.

If parents decide to stop vaccinating, health officials say we will see a resurgence of disease outbreaks, the likes of which we have not witnessed in several decades. Thousands of children will be at risk from the crippling effects of polio, the debilitating scourge of rubella, and the deadly toll of tetanus and diphtheria.

—STEPHANIE WATSON

KEY TERMS

ALLERGIC REACTION:

Heightened reaction to a substance (allergen) that triggers abnormal responses in the body's protections system (immune system).

ANTIBODY:

Protein produced in the blood as part of an immune response to a foreign substance in the body.

ANTIGEN:

Foreign substance that stimulates the body's immune response.

DIPHTHERIA:

Disease in which the bacteria Corynebacterium diphtheriae produce a deadly toxin that produces a thick gray coating in the back of the throat, which in turn inhibits breathing and swallowing.

HEPATITIS B:

Contagious, viral liver disease leading to liver failure and liver cancer, causing approximately 5000 deaths a year and remaining dormant but contagious in symptomless, unsuspecting "carrier" individuals capable of spreading the disease.

HAEMOPHILUS INFLUENZAE TYPE B (HIB):

Bacteria responsible for one type of meningitis.

MEASLES:

Respiratory disease caused by virus that grows in the cells that line the back of the throat and lungs.

MUMPS:

Disease in which bacteria of the genus

Paramyxovirus causes inflammation of various body parts, particularly the parotid glands.

PERTUSSIS (WHOOPING COUGH):

Disease caused by Bordetella pertussis that causes severe coughing spells that can last for several weeks.

POLIO:

Acute viral disease causing paralysis, permanent disability and death.

RUBELLA (GERMAN OR THREE-DAY MEASLES):

Respiratory disease characterized by a rash, fever, and swollen lymph nodes.

TETANUS (LOCKJAW):

Disease caused by Clostridium tetani. Symptoms include a painful tightening of the muscles, which often includes "locking" of the jaw so that the patient cannot chew or open his mouth.