Fact or Fiction?
Benefits vs. Risks
FACT: The benefits of preventing disease with a vaccine far outweigh the risks.
Any medicine can cause side effects, but serious side effects from vaccines are very rare.
It’s normal to have questions about possible vaccine risks, especially when the benefits seem invisible. If your child is protected with vaccines, you won’t know when they are exposed to a vaccine-preventable disease. You won’t know how often their vaccine-induced immunity protects them from getting sick. Fortunately, we have strong data to help caregivers like you weigh the pros and cons. Here’s what you need to know.
Immunization saves lives.
The primary benefit of immunization is that it prevents disease. Immunization, also called vaccination, is one of the world’s greatest public health achievements. Experts agree that immunization is key to staying healthy. In one year, vaccines prevent more than 8,600 child hospitalizations in Colorado, 31,000 deaths in the U.S., and between 4 and 5 million deaths worldwide.
Immunization has decreased the rate of disease dramatically.
| Disease | Peak Cases in Pre-Vaccine Era (Year) | 2017 Cases | Percent Decrease |
| Measles | 763,094 (1958) | 99 | 99.9% |
| Diphtheria | 30,508 (1936) | 0 | 100% |
| Mumps | 212,932 (1964) | 6,109 | 97.1% |
| Pertussis (Whooping Cough) | 265,269 (1934) | 18,975 | 82.85% |
| Smallpox | 110,672 (1920) | 0 | 100% |
| Rubella | 488,796 (1964) | 7 | 100% |
| Polio (paralytic) | 21,269 (1952) | 0 | 100% |
| Tetanus | 601 (1948) | 33 | 94.51% |
These decreases 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. If we stop vaccinating, vaccine preventable-diseases can and will return. This is why we still vaccinate against diseases that are rare in the U.S. An outbreak can occur if just one infected traveler enters the U.S. from a country where a disease is circulating. In fact, almost all recent U.S. measles outbreaks have started after unvaccinated U.S. travelers brought the disease back home after a trip.
Vaccines are safe.
Vaccines go through strict safety testing prior to approval by the Food and Drug Administration (FDA). After they are approved, vaccines are closely and continuously monitored for safety using several different systems. Vaccines are also studied to be given at the same time.
Researchers have studied the vaccine schedule and vaccine safety in depth. In May 2021, the Agency for Healthcare Research and Quality reviewed nearly 200 studies on vaccine safety. They published a report on their review. It found no evidence of major safety concerns connected to the childhood immunization schedule.
Immunization protects the people you care about.
Immunization is not just a personal choice. Vaccinated people help to protect those who are not vaccinated. This is a concept known as “herd immunity” or “community immunity.” When a person is vaccinated, they prevent disease from spreading to people close to them and to others in the community. This is especially important for people who cannot get vaccines or are at high risk from disease complications. This includes:
- Babies too young to receive vaccines
- Pregnant women
- The elderly
- Individuals with weakened immune systems and people with other health conditions like asthma, chronic illness, or cancer
- People who are allergic to vaccine components
Most children in the U.S. are vaccinated, but some are missing some or all vaccines. Sometimes unvaccinated people cluster in certain geographic areas, increasing the chance for disease outbreaks. When immunization rates drop, infectious diseases can spread more easily. Likewise, when more people in a community are vaccinated, disease is less likely to spread. The level needed to protect a community through herd immunity is different for each disease.
For very contagious diseases, like measles, roughly 95% of people in a community need to be vaccinated to protect against outbreaks.
Vaccines drastically reduce the likelihood of getting sick.
Sometimes during an outbreak, more vaccinated children get sick than unvaccinated children. This is simply because there are more vaccinated kids than unvaccinated kids, and vaccines are not 100% effective.
For example: Pretend there are 200 6th graders at ABC Middle School, and 90% (180) of them are vaccinated. Due to an outbreak, the ABC Middle School is exposed to pertussis (whooping cough). Of the 180 vaccinated students, 29 get pertussis. Of the 20 unvaccinated students, 16 get pertussis. More vaccinated students got pertussis, so it may seem like vaccinated kids are more at risk. In reality, 80% (16 out of 20) of unvaccinated kids were infected, while just 16% (29 out of 180) of vaccinated kids were infected. Additionally, people who are vaccinated and do get sick are less likely to get severely ill compared to those who are unvaccinated.
Vaccines save money.
Not only do vaccines save lives, they also save money. It is cheaper to prevent a disease than to treat it. For all the children born in the U.S. in one year, routine immunization saves more than $63.6 billion in societal and healthcare costs across their lifetime. Every $1 spent on childhood immunization saves $10.90. In just 1 U.S. state (Colorado), the cost of treating 3,458 kids hospitalized for vaccine-preventable diseases in 2022 totaled $252 million.
The risks of natural infection outweigh the risks of immunization for every recommended vaccine.
Some people might wonder if natural immunity from a disease is better than immunity from a vaccine. Immunity after infection usually provides some protection against future infection. But, the only way to get this immunity is to get sick first. Getting sick comes with risk for complications. For example, the risk of encephalitis (brain infection or swelling) from measles is 1 in 1,000 and the risk of pneumonia with measles is 1 in 20. In comparison, the risk of serious allergic reaction from the measles vaccine is 1 in 1 million. The great thing about vaccines is that they provide strong, often life-long immunity without causing infection.
Parents who choose not to vaccinate often do so to avoid risk. However, choosing not to vaccinate is the riskier choice.