Surprising Facts You Might Not Know About Vaccines

You can do a lot in your daily life to prevent disease, stay in shape, and set yourself up for a long, healthy life. However, not even the healthiest habits can protect you from all illnesses. And vaccines are the most effective way to protect yourself — and those around you — from the world’s deadliest diseases.

There’s a lot you might not know about vaccines, too, like how they started, how they’re developed, whether they’re safe, and how effective they are. Let’s take a closer look at everything you might not know about vaccines.

1. Immunizations began with smallpox

The first vaccine was developed to immunize against smallpox.

An 8-year-old boy received the first ever vaccine. |

Smallpox was the first vaccine-preventable disease we eradicated — and the only one thus far. According to, Edward Jenner developed this first vaccine in 1796. Nearly 100 years later, Louis Pasteur developed a rabies vaccine, then the polio vaccine followed in the mid-1900s. Scientists have since developed vaccines for a number of illnesses that used to cost thousands of people their lives.

Next: Here’s how scientists know if a vaccine is safe or not.

2. A vaccine goes through many tests before it’s given to the public

All vaccines are safe. If they weren't, they wouldn't be available to you.

Vaccines go through years of trials and approval processes. |

Every vaccine you get has been through layers upon layers of trials and licensing. Officials would never allow providers to give out a vaccine that wasn’t safe, after all. According to the Centers for Disease Control and Prevention, new vaccines go through a multi-step process even before they’re administered. This process involves careful testing and monitoring before, during, and after a vaccine is made. Then, clinical trials involving thousands of human subjects test whether or not a vaccine works and if it’s safe. There’s also a specific surveillance program, called The Vaccine Adverse Event Reporting System, that tracks reported side effects of vaccines around the country once they’re publicly available.

Next: There’s a reason kids get so many vaccines when they’re young.

3. Vaccines can protect against more than a dozen diseases

Vaccines prevent a number of deadly diseases.

Vaccines will protect you against many diseases that once killed thousands. |

There’s a reason we have to get so many vaccines when we’re young — and even some when we’re older. Scientists have developed vaccines to protect people against more than a dozen deadly illnesses worldwide. MedlinePlus offers a list of common vaccines administered both in childhood and adulthood in developed countries to prevent a number of potentially fatal diseases. These include:

  • Chickenpox
  • Diphtheria, tetanus, and pertussis
  • Hepatitis A and B
  • Haemophilus influenzae type B (Hib)
  • HPV
  • Influenza
  • Meningococcal disease
  • Measles, mumps, and rubella
  • Pneumococcal conjugate and polysaccharide diseases
  • Polio
  • Rotavirus

Next: One vaccine-preventable disease down. Almost another on its way out.

4. Vaccines have almost eradicated two other diseases

We could erase more disease with more widespread vaccinations.

Bye, smallpox. |

Vaccines work. There’s just as much evidence to show their effectiveness when we use them as there is to show what happens when we don’t. For example, the CDC reports that three out of every 10 people who developed smallpox used to die from it. Now, because of the smallpox vaccine, it’s no longer an immediate threat. And polio isn’t far behind. According to the World Health Organization, there were only 37 cases of polio reported worldwide in 2016. However, as long as there’s even just one child infected with polio, thousands more are at risk. The more people the polio vaccine can reach, the greater chance we have of eradicating it from the planet for good.

Next: Just how many lives do vaccines save?

5. Vaccines save millions of lives every year

Vaccines save lives.

Vaccines have, and will continue to, prevent fatalities from deadly disease. |

When your children were vaccinated, it probably seemed like nothing more than a routine procedure. In reality, though you might not have thought much about it, those injections may have saved your child’s life. Here in the U.S., we’re so used to vaccines preventing the majority of deadly diseases that we don’t always consider how many lives they save every year. According to the World Health Organization, measles vaccinations alone saved more than 17 million lives between 2000 and 2015. Though vaccines aren’t a 100% guarantee that you won’t contract a disease, they’re the most important step in preventing — and hopefully eradicating — some of the worst diseases on the planet.

Next: It may be more cost-effective to get vaccinated.

6. Vaccines save billions in health care costs

Vaccines are less expensive than containing outbreaks of disease.

It’s much more expensive not to get vaccinated. |

Sometimes, an expensive vaccine seems like a valid reason for hesitation. But that’s a short-term view. A study published in the journal Pediatrics looked at the cost benefits of a number of vaccines compared to the cost of the diseases they prevent. Getting sick with a vaccine-preventable disease costs much more than the vaccine itself, especially in the long-term. When one person contracts a disease it can result in an outbreak — which would cost thousands of dollars per day to contain.

Next: Vaccines don’t cause autism — but where did the myth come from?

7. The misconception that vaccines cause autism is basically one guy’s fault

There is no evidence that the MMR vaccine causes autism.

It all began in 1998. |

In 1998, Andrew Wakefield and colleagues published research suggesting the MMR vaccine caused autism in children. According to the Immunization Action Coalition, this research was not invalid, but Wakefield also received undisclosed funding to conduct it. He was banned from practicing medicine in the U.K., and in 2010, The Lancet permanently retracted the study.

Unfortunately, science hasn’t stopped many from trusting Wakefield’s “research” anyway. Fears that vaccines are to blame for autism spectrum disorder cause parents to question whether they’re safe, despite health officials’ assurance they won’t make children sick. If you’re interested in reviewing the research for yourself, put together a list of evidence refuting claims that thimerosal, the MMR vaccine, and normal childhood vaccine schedules cause autism. There simply isn’t evidence to support this myth, meaning parents who opt out of childhood immunizations are putting children at risk.

Next: Is there still thimerosal in vaccines?

8. Mercury-free vaccines are pretty much the norm

Most vaccines are thimerosal-free.

Very few vaccines still contain this preservative. |

According to MedlinePlus, only about a third of flu shots still contain thimerosal. The mercury-containing preservative was once common in most vaccines. Other than some flu shots, no other vaccines still contain thimerosal. However, even if they did, there isn’t any research to support the claim this preservative causes any kind of medical issues. Also, the FDA does note that all vaccines regularly given to children ages 6 and under are automatically thimerosal-free.

Next: The way vaccines are administered prevents you from getting sick from a live virus.

9. Vaccines can’t give you the disease they’re preventing

Dead or weakened viruses can't make you sick.

Vaccines don’t cause disease — they prevent it. | Ammentorp Lund

Vaccines involve injecting a dead or weakened virus or bacteria to introduce it to your immune system. However, this does not mean you’re likely to get sick. According to the CDC, it’s not possible to contract a disease from a dead bacteria or virus, or a weakened live specimen. Sometimes kids seem to develop a very mild case of a disease after vaccination. However, experts promise this doesn’t cause harm. In fact, it can actually signal that a vaccine is doing what it’s supposed to be doing — preventing disease.

Next: Antibiotics may be getting a new enemy: vaccines.

10. They’re an important defense against antibiotic resistance

Antibiotic resistance is a growing possible threat.

There aren’t vaccines for common bacterial infections — yet. |

Vaccines might help medicine win the fight against antibiotic resistance. According to the World Health Organization, the overuse and misuse of antibiotics has become a major public health concern. Thankfully, vaccines could help protect more people from disease, and reduce the need for so many antibiotics in the future. There aren’t yet vaccines to treat many of the illnesses doctors prescribe antibiotics to treat, like strep throat, but future vaccines could reduce the prevalence of antibiotic prescriptions, and even halt resistance before it becomes a deadly issue.

Next: If a disease still exists, only a vaccine can protect you.

11. You need a vaccine even if a disease is almost gone

Anyone who is able should get vaccinated.

You’re not immune without a vaccine. |

Just because many diseases are now uncommon in the U.S. doesn’t mean you shouldn’t still get vaccinated. Certain diseases could come back to harm us if we don’t keep vaccinating against them. The CDC warns that vaccines don’t just protect you in the present or near future. They protect everyone around you, too — including your future children, and their children, and their children. Certain people cannot receive vaccines — not just infants, but people with certain medical conditions as well. They depend on those with healthy immune systems, who can receive vaccines, to keep deadly diseases away.

Next: Don’t like needles? You might be in luck.

12. Vaccines could become needle-free

One day you might not get vaccinated via an injection.

Needle-less vaccines might even be safer, eventually. |

At the moment, most vaccines are administered via injection. However, some research in animals suggests oral immunizations could become an alternative delivery method in the distant future. This is good because using needles, even in medical settings, always poses some risk of contamination or human error. A needle-free vaccination method could potentially prevent these types of risks.

Next: Can pregnant women get vaccinated — and should they?

13. Immunization can begin in the womb

Immunize your baby before it's born.

A few vaccinations are actually recommended late in pregnancy. |

A mother starts caring for her child long before they’re born, and vaccines are one way mothers can protect their infants from disease while still pregnant. Some shots are even recommended during pregnancy. According to Mayo Clinic, physicians typically recommend pregnant women receive both flu and Tdap vaccines. This protects the mother, and will also give the baby protection until it’s old enough to receive its own immunizations. This is especially important since both the flu and whooping cough (pertussis, the ‘p’ in Tdap) are dangerous for infants.

Next: What happens to kids whose families can’t afford vaccines?

14. There’s a program in the US that vaccinates kids for free

VFC provides vaccines for kids who can't afford them.

Kids who can’t afford it can get vaccinated for free. |

Though vaccines are extremely important to ensure optimal public health, they aren’t always affordable. In attempt to provide vaccines for everyone who wanted but couldn’t afford them, the government established a free immunization distribution initiative. The Vaccines for Children program provides free vaccines to children whose families can’t afford them. If eligible, children who might otherwise go without more than a dozen vaccines have the option to receive them for free. To take part in the program, families must meet one of several requirements. Children whose insurance covers the cost do not qualify.

Next: Do adults need vaccines, too?

15. They aren’t just for kids

Adults need certain vaccines, too.

Get your shots, no matter how much you’re still afraid of them. |

Childhood immunizations make up a large percentage of the vaccines we receive throughout our lives. However, adults can — and should — receive certain vaccines as well. The CDC recommends all adults get an influenza vaccine yearly, plus a Td vaccine every 10 years. Some factors might add to these recommendations. The HPV vaccine, for example, is recommended for women up to 26 years of age. University employees are often asked to get a meningitis vaccine, too, because college students are at higher risk of contracting and spreading the disease.

Read More: The Rare and Deadly Diseases You Might Not Know About, But Should