Vaccines and Public Health

Ranking right next to Climate Change as an issue where majority scientific opinion meets passionate dissent, the safety of vaccines elicits passionate and wildly different perspectives. For many doctors, especially those in public health, vaccines are a no brainer. As we have advanced as a civilization, diseases that used to cause significant harm and even prove fatal have been dramatically transformed by the introduction of vaccines Measles – the subject of much of the political debate mentioned above – used to send approximately 48,000 people a year to hospitals in the United States. Most people survived these complications, but some faced ongoing health problems for many years.

Due to the introduction of a measles vaccine, along with other careful eradication efforts, measles now occurs in less than 1 person per million in the United States. In a country where the disease and its side effects have become increasingly rare, it can be easy to forget how deadly it can be. According to the the World Health Organization, in the absence of measles vaccines, 4.5 million children would die annually as a result of the disease and its complications.


Vaccine Skeptics

However, despite the overwhelming personal and public health benefits of vaccines, a subset of the population chooses not to vaccinate their children. These people come from a variety of backgrounds, with particularly strong representation in libertarian and holistic health circles. The nature of this opposition ranges from curious and concerned parents looking for information, to impassioned evangelists who believe in a conspiratorial coverup by health authorities to scare the population into compliance.

No journey into the potential dangers of vaccines can get far without the mention of autism. Likely the origin of many people’s opposition to vaccines, and undoubtedly the most often cited concern, is the theory that vaccines cause autism. As many now know, this theory originated with a paper published in the British journal The Lancet. The paper caused widespread concern, speculation, and rumor, and has since been countered by a large body of evidence including evidence that Andrew Wakefield, the paper’s author, apparently falsified evidence to establish the link.  The paper has subsequently been retracted and its author barred from practicing medicine.

Despite this overwhelming evidence, the paper left a deep impression on many people who still believe in a vaccine autism link.

But what of other dangers? For those who accept that Wakefield’s work was fraudulent and accept the science disproving it, many still have concerns about other dangers related to vaccines.

In the face of mounting evidence against a vaccine and autism link, questions arose around the connection between heavy metals like mercury and the disease. Extensive studies have show that this too is almost certainly false.

The nonprofit Institute of Medicine, produced a report detailing extensive study into peer-reviewed literature covering eight major vaccine-preventable diseases given to children and adults in the U.S. The committee looked at epidemiologic, biological and clinical evidence to understand how vaccines affect the human body. The report lists the risks of each vaccine, and weighs them against the complications of the corresponding disease. The report concludes that most adverse side effects are minor and manageable, but also acknowledges that more study is necessary to understand “how the human immune system…and the effects of genetic variation…may influence how people respond to vaccines.”

Some vaccine skeptics believe that vaccines compromise the ability of the body to fight off disease by preventing the body from producing natural immune responses. However this may result from misunderstanding the biological mechanism of how vaccines work with the immune system. Essentially, vaccines trigger the same response in the immune system as if the human body were to catch the disease itself (see infographic for more detail).

While disease induced immunity can last longer than immunity from a vaccine for many diseases, the risks of infection must be weighed against the risks of not getting vaccinated (see infographic for details).

Some vaccine skeptics are also concerned that overuse of vaccines will lead to the same risks of disease resistance as the overuse of antibiotics. To compare how the vaccine mechanism and risks are different from those of antibiotics, see our infographic at the top of this page.

There are numerous other vaccine-specific fears that skeptics have, and that diversity of fear is reflective of the diversity of people’s conclusions on what to do about vaccination. It’s not a clear pro and anti-vax debate, and this shows as more parents begin to choose alternative or delayed schedules of vaccination.


The Return of Diseases

While the choice to vaccinate oneself and one’s family can be deeply personal, it also has societal implications. Disease spreads. Public health officials often speak of a concept called Herd Immunity, which shows that when a certain critical mass of a population is immunized, the further spread of disease is contained.

However, when a significant percentage of the population rejects immunization, disease continues to advance.

When Wakefield published his now debunked paper, immunization rates in Europe dropped.

Measles is now on the rise.

Measles was declared eradicated in 2002, but is now back, with a 20-year high in reported cases (554 cases from January 1 to July 3, 2014). Most cases have occurred in unvaccinated travelers, who then became sources of transmission when exposed to unvaccinated US natives.”

This is one of the reasons we need a clear understanding of the safety of vaccines. Rumor and speculation can cost people their lives. Moreover, the cost to society to contain the spread of disease is significant, diverting labor and financial resources in the public health department away from their work.

If credible science does uncover dangerous side effects in a particular vaccine, those findings need to be made clear and alternative treatments need to be proposed. While the Federal government currently plays an active role in investigating all vaccines and shares its findings, there is need for improvement, especially in reporting cases of medical fraud and potential conflict of interests. However, a blanket fear of vaccines based on unsubstantiated theories and debunked science need to be understood as equally dangerous.


The Flu

Unlike measles, influenza is combated with a series of vaccines that attempt to estimate which flu strains are likely to be abundant in a given season. Despite the advice of most doctors and CDC recommendations for universal flu vaccination, many healthy adults forgo the shot each season. Successfully avoiding the flu each season leads many to see no purpose in getting the vaccine. Additionally some mistakenly believe that its possible to contract the flu from the vaccine itself. Both of these are worth examining when one understands the impossibility of the latter – a confusion often arising out of symptoms unrelated to influenza that can occur after a shot – and the possibility of spreading the virus. While a healthy adult many only have a rough weekend after contracting the flu, it is possible to spread the virus to someone with a weak immune system who may experience more serious consequences. Nonetheless such population health concerns are hard to see and for many will still get outweighed by a general distaste for vaccines.



Vaccines are not a single thing. They are a category of medicine, made up of a variety of ingredients. Most vaccines are thoroughly tested and a large body of evidence exists to demonstrate their safety. In almost all cases the risks associated with the disease, for oneself and society, far outweigh those of the vaccine.

Vaccines skeptic, like all parents, have the right to be concerned about the safety of any substances that enter their or their children’s bodies. Individuals also have legitimate concerns about ceding control of their children’s health care to government regulations. However, a large body of evidence exists to support the benefits vaccines have had on both public and individual health, and as diseases like measles return to unvaccinated populations, the risks of not getting vaccines must be clearly understood. Both for individual health, and for the risks posed to those more susceptible to disease or to individuals unable to be vaccinated, the science conducted so far leans strongly in the direction of vaccine safety.