Childhood immunizations are one of the most significant public health advances in medical history. Thanks to vaccines, most children and teens today may never even have heard of, let alone experienced, such afflictions of earlier generations as polio, smallpox, measles and mumps.

While the general consensus is that vaccines are here to stay, critics of childhood vaccination say there’s a hidden side of the common practice that might make parents think twice before letting a doctor inject their child. What are the issues driving the vaccine debate, and what do parents need to know before deciding for themselves whether vaccines hurt or help?


Vaccines work by introducing a weakened or deactivated form of a disease into the body. The immune system then recognizes and destroys the foreign agent, giving the body a "training exercise" through which it can develop antibodies and form an immunity—all without having to get sick. If that the person is exposed to that disease again, the immune system can neutralize the threat before it takes hold.

Because of high vaccination rates in the United States and growing rates worldwide, incidence of such vaccine-preventable diseases as measles, mumps, and polio have decreased dramatically over the last century. Worldwide measles deaths alone decreased 74% from 2000 to 2007. This is directly attributable to the phenomenon of “herd immunity": when a large percentage of a given population is immune to a disease, the non-immune individuals are also protected since there are few vectors for the disease to travel from one person to another.

An increase in the number of measles outbreaks is the United States—which include the 644 confirmed cases in 2014, the most since 1994, and the large, multi-state outbreak attributed to an amusement park in California—has made vaccination (and the decision some parents make not to vaccinate their children) a hot topic among parents, public policy experts, and medical professionals. The majority of people who contracted measles in 2014 were unvaccinated. Because measles is highly contagious and can linger in the air for up to 2 hours, it can spread through schools and health care settings like wildfire, often threatening those most at risk, such as pregnant women, babies, and those with weakened immune systems due to diseases like AIDS or cancer—all of whom rely on herd immunity for protection. California's current whooping cough epidemic—which began in 2014 and is the worst outbreak on record since World War II—has already claimed the lives of two infants who were too young to receive the vaccine for the disease and would have relied solely on herd immunity for protection.


Resistance to the idea of vaccination is as old as the invention of vaccines themselves, with disputes ranging from the effectiveness and safety of vaccines to the threat to civil liberty that compulsory vaccination campaigns could pose.


Fear among the general public over the safety of immunization has formed the backbone of the anti-vaccine movement, which offers some anecdotal evidence to support claims of damage due to vaccination. In the 1970’s and 80’s, several cases of brain injury and seizures were linked to the pertussis (whooping cough) portion of the DPT vaccine, prompting a legal backlash that threatened to put vaccine manufacturers out of business.

As a result, the National Childhood Vaccine Injury Act (NCVIA) was passed in 1986, establishing a federal “no-fault” system to compensate victims of injury caused by vaccines, which include allergic reactions (anaphylaxis and anaphylactic shock), brain injury (encephalopathy), and seizures and convulsions. The pertussis vaccine has since been modified to make it safer, but the older strain is still administered in developing countries, as it is cheaper to produce.

In 1998, a study suggesting a connection between the MMR vaccine and autism was published in the prestigious medical journal The Lancet, launching a frenzy of media attention and public uproar. Many parents, both in Europe and the United States, began to refuse the vaccine for fear of an autism link, and many still believe that the MMR vaccine bears some of the blame for their child’s autism. These parents say that they have observed the same pattern: their child was a normally developing one-year-old, but after the shot, symptoms of autism, such as disinterest in social interaction, began to manifest.

However, it has not been determined that the onset of autism at around the same time as the administration of the MMR vaccine is a causal relationship. The Lancet has since retracted the 1998 study after an investigation by the British General Medical Council established the results of the study as deliberately falsified. As a result of the same investigation, the study's lead author, Andrew Wakefield, was found guilty of three dozen charges, including four counts of dishonesty and twelve counts of abusing the developmentally disabled children used in his research. Since 2010, he has been barred from practicing medicine in the UK.

A host of valid studies have been released to debunk the connection between autism and vaccines, but anti-vaccination organizations have continued to ask for further government testing of vaccines and the possible dangers they pose.


Some anti-vaccination activists object to the unnatural quality of the vaccination practice, preferring, instead, the more traditional process of contracting a disease naturally, such as measles and chickenpox, which, after recovery, gives the person life-long immunity. “Once you get measles and recover, you’re immune for life,” claims Neil Miller, a medical research journalist and author of Vaccines: Are They Really Safe and Effective?. “The vaccine itself does not confer permanent immunity. This is why they’ve developed this idea of booster shots. What is the medical industry’s answer to an ineffective vaccine? It’s to give more of it.”

But Wayne Yankus, MD, a community pediatrician in New Jersey, suggests that the notion of lifelong immunity for those naturally exposed to a disease in childhood may be unraveling. He points out that adults are living longer than ever before, and that waning immunity may be possible in old age even when someone had, say, chickenpox as a child. However, Yankus acknowledges that there is a small percentage for whom immunization just doesn’t work (in the case of measles, around 2-5% of people are still vulnerable to the disease after their first dose of the vaccine, and 1% are vulnerable after receiving one booster shot). The fix? These individuals are protected by the vast majority of people for whom vaccination does work. “We count on herd immunity, which is why we require immunizations for school.”

A Parent’s Rights

The vaccine debate has also lead to a controversy over the role of government versus the right of a parent to make choices regarding their child’s health. At present, choosing to refuse vaccination for your child is not illegal, but it is mandated as a requirement for your child to attend public school (exemptions for religious or medical reasons, and sometimes for philosophical ones as well, are available but sometimes difficult to obtain).

Public health authorities view large-scale vaccination as an essential key to preventing epidemic diseases. Individuals, however, often weigh the “big picture” of public health against perceived dangers to one’s individual child. Because of the “herd immunity” of the general population, the decision not to vaccinate a single child might seem safe on an individual basis. But, says Yankus, parents today lack perspective on the dangers posed to others by refusing immunization. “The issue with immunizations in general is that because so many parents today have never seen these diseases or known what they can do, many parents choose not to immunize, which is a huge mistake,” he says. “I grew up with many of these diseases. I had a college roommate who died of measles encephalitis. I had a neighbor who contracted polio.”

Now, says Yankus, people have the luxury to worry because they have not been exposed to the risks. “Now there is a strong, forceful, poorly informed, non-scientific community of people who feel that they don’t have to immunize. As a consequence, their behavior puts everyone at risk.”

Does that mean that a parent doesn’t have a right to choose? Legally, they do. But that doesn’t mean the government hasn’t instituted hoops that parents need to jump through. Sending your child to private school is one option. Another is to apply for a religious, medical, or philosophical exemption to the rules governing public school enrollment. But, says Miller, that doesn’t stop doctors from trying to vaccinate at all costs. “Kids are not legally required to get vaccinated. But doctors may try to intimidate them and frighten them with scare tactics,” he says. Yankus says that his pediatric practice does not take patients who refuse vaccination. “I do not have any reason in this day and age to take care of diseases that are preventable,” he says, but notes that parents are welcome to make their own choice in the matter.

The consensus of the medical community is that vaccines are a safe and integral part of public and individual health. But for parents who still find themselves undecided on the issue, here are some steps to take before making your final decision:

  • Talk to your pediatrician about your concerns. Bring specific examples of why you are worried about the vaccine, and listen to what he or she has to say.
  • Know your rights. It is not illegal to refuse vaccination. However, public schools require that children be vaccinated as a prerequisite for enrollment. Exemptions for medical and religious reasons are usually available, and exemptions for philosophical ones less so.
  • Be informed, and know the research. Anecdotal evidence and stories from other parents can be persuasive, but pay attention to scientific studies that show reproducible results.