Fact Or Fiction

Benefits vs. Risks

FACT: The benefits of preventing disease with a vaccine far outweigh the risks.”

Any medicine can cause reactions, but serious vaccine side effects are very rare.

It’s natural to want to understand the potential risks of vaccination, especially when the benefits are invisible. You’ll never know how many times your child is exposed to a vaccine-preventable disease and makes use of his or her vaccine-induced immunity. Fortunately, we have sufficient data to help parents like you weigh the pros and cons. Here’s what you need to know.

Vaccination saves lives.
The primary benefit of vaccination is that it prevents disease. Immunization is considered one of the greatest public health achievements of the 20th century, and experts agree that immunization is key to staying healthy. In one year, vaccines prevent more than 8,500 child hospitalizations in Colorado, 33,000 deaths in the U.S., and between 2 and 3 million deaths worldwide.

Vaccination has decreased the rate of disease dramatically.

Disease Baseline 20th Century Annual Cases 2006 Cases Percent Decrease
Measles 503,282 55 99.9%
Diphtheria 175,885 0 100%
Mumps 152,209 6,584 95.7%
Pertussis (Whooping Cough) 147,271 15,632 89.4%
Smallpox 48,164 0 100%
Rubella 47,745 11 99.9%
Haemophilus influenzae type b, invasive (HiB) 20,000 29 99.9%
Polio 16,316 0 100%
Tetanus 1,314 41 96.9%

Source: The Impact of Vaccines in the United States

These drops in disease rates are primarily thanks to vaccination, not sanitation or improved hygiene. (If that were the case, all diseases would start declining around the same time.) While the diseases we vaccinate against have declined, they haven’t disappeared. While vaccines have become increasingly accessible in the U.S., other countries are not so lucky. As we have seen in the U.S. and in other countries, if we stop vaccinating, vaccine preventable diseases can and will return. This is why we still vaccinate against diseases we no longer see in the U.S. All it takes is one infected traveler from another country where a disease hasn’t been eliminated to spark an outbreak.

Vaccination protects the people you care about.

Vaccination is not just a personal choice. The vaccinated community helps to protect those who are not vaccinated, a concept known as “herd immunity” or “community immunity.” Simply put, when a person is vaccinated, they prevent disease from being spread to others in the community, including:

  • Babies too young to receive vaccines
  • Unvaccinated children and adults
  • Pregnant women
  • The elderly
  • Individuals with weakened immune systems, such as those with asthma, chronic illness, or undergoing treatment for cancer
  • Individuals who are allergic to vaccine components

When less than 90% of children are immunized in a particular community, these pockets of low vaccination create an environment where infectious diseases can take hold and spread. Only a very small percentage of children in the U.S. are completely unvaccinated—about 3%—however, they tend to cluster in certain geographic areas. Clustering of unvaccinated individuals in certain communities diminishes the benefits of herd immunity for everyone living in that area.


Herd Immunity Threshold Required











Did you know? A new Colorado law allows anyone to request school and child care center immunization and exemption rates. Learn more to see which schools and child care centers may be the safest for your child.

When vaccine-preventable disease outbreaks occur, vaccine critics like to use the tricky point that more vaccinated children become infected than non-vaccinated children. This is true, but simply because there are more vaccinated kids than unvaccinated kids, and vaccines are not 100% effective.

For example: Let’s pretend that there are 200 6th graders at ABC Middle School, and 90% (180) of them are vaccinated. Due to a major outbreak, the ABC Middle School is exposed to pertussis (whooping cough). The “attack rate” among the vaccinated kids is 16%, so 29 of the 180 vaccinated students get pertussis. However, the “attack rate” among the unvaccinated is 80%, so out of the 20 unvaccinated students 16 become infected. This can make it appear as if vaccinated kids are at greater risk, but in reality 80% of unvaccinated kids were infected while just 16% of vaccinated kids were infected.

Vaccines are cost effective.
Not only do vaccines save lives, they save money too. It is always cheaper to prevent a disease than to treat it. The routine childhood immunization program in one birth cohort saves $13.6 billion in direct costs. Every dollar spent on childhood immunizations saves $18.40. In Colorado, the cost of treating 538 children hospitalized for vaccine-preventable diseases in one year totaled $29.2 million.

Vaccines are safe.
Vaccines undergo rigorous safety testing prior to being approved by the Food and Drug Administraton (FDA) and are continually monitored for safety. Vaccines are also studied to be administered together to protect children.

In January 2013, the Institute of Medicine (IOM) published the most comprehensive examination of the immunization schedule to date, and the report uncovered no evidence of major safety concerns associated with adherence to the CDC-recommended childhood immunization schedule.

What does the Institute of Medicine (IOM) Say about Vaccine Safety?

  • “The current recommended U.S. childhood immunization schedule is timed to protect children from 14 pathogens by inoculating them at the time in their lives when they are most vulnerable to disease.”
  • “Before the ACIP recommends adding a new vaccine to the immunization schedule, it reviews comprehensive data about that vaccine’s safety and efficacy in clinical trials, injuries and deaths caused by the disease the vaccine is designed to combat, and the feasibility of adding the new vaccine into the existing schedule, among other factors.”
  • “Delaying or declining vaccination has led to outbreaks of such vaccine-preventable diseases as measles and whooping cough that may jeopardize public health, particularly for people who are under-immunized or who were never immunized.”
  • “States with policies that make it easy to exempt children from immunization were associated with a 90 percent higher incidence of whooping cough in 2011.”
  • “…the IOM committee finds no evidence that the schedule is unsafe. The committee’s review did not reveal an evidence base suggesting that the U.S. childhood immunization schedule is linked to autoimmune diseases, asthma, hypersensitivity, seizures, child developmental disorders, learning or developmental disorders, or attention deficit or disruptive disorders.”

The risks of natural infection outweigh the risks of immunization for every recommended vaccine.
Parents who choose not to vaccinate often do so to avoid risk, but choosing not to vaccinate is the riskier choice.

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