Despite an abundance of scientific evidence proving that vaccines are a safe and effective means of preventing life-threatening illnesses, a few myths persist that may make some parents hesitant. Here Dr. Elizabeth Dennison with Lexington Pediatric Practice sorts the myths from the facts. 

1. Vaccines contain many harmful ingredients.

In addition to antigens, vaccines contain other elements that help your immune system respond more strongly to a vaccine. These elements are naturally occurring substances often present in our diet - like aluminum and sodium chloride (table salt). These elements are in very small amounts that are not concentrated enough to harm the body. 

Vaccines also contain preservatives like formaldehyde to protect them from outside germs and bacteria. You may be surprised to learn that small amounts of formaldehyde naturally occur in our bodies. It is required to serve as the building blocks for proteins and DNA, and the natural amount in the body is much higher than in a vaccine. 

Vaccine ingredients have been proven safe. 

2. Vaccines cause autism and sudden infant death syndrome (SIDS).

The initial study that proposed vaccines cause autism was retracted in 2010. While it became a prevalent myth in our culture, no scientific studies have supported this causal relationship. 

It is important to note that studies have shown that vaccines actually help prevent sudden infant death syndrome (SIDS.) 

3. Vaccine-preventable diseases are just part of childhood. It is better to have the disease than become immune through vaccines.

Vaccine-preventable diseases do not have to be a part of childhood. Many of these vaccine-preventable diseases, like measles, varicella (chicken pox), and pertussis can cause serious illness or even death if a child were to become infected. Developing immunity through vaccines means we can prevent the serious consequences of a primary infection with the disease. 

4. I don’t need to vaccinate my child because all the other children around them are already immune.

One of the most important ways to prevent the spread of disease in our community is through what we call “herd immunity.” This means that the vaccine rate in a community should be high enough to protect the most vulnerable (those who cannot get the vaccine) from contracting the disease. If vaccination rates in a community are not high enough, there can be “breakthrough cases,” and the risk of infection becomes much higher. That is why each child needs to be vaccinated against the disease if they are able.

5. You can actually get the disease from a vaccine.

Vaccines typically contain weakened or inactivated (“killed”) forms of the disease they protect against. Though your child may develop a low-grade fever or feel a little tired after receiving a vaccine, their body is working to mount an immune response to protect them from that disease in the future – it does not mean that the child has been infected with the disease. By incorporating the weakened or killed version of the disease into the immune system, the body can fight off the disease better should the child encounter it in the future.

If you have questions or concerns about vaccines, it is important to talk with your child's health care provider. 


Elizabeth H. Dennison, MD, Lexington Pediatric Practice