How Vaccines Work

How Vaccines Work

Knowledge is power. We also think knowledge is the best defense against fear. Many parents base their decision not to vaccinate on fear of the unknown. We get that. The environment we are raising our children in is quite a bit different than the one we were raised in; we are now much more aware of the multitude of toxins that our children are exposed to. So, perhaps the best place to start researching your decision to vaccinate (and get the power) is to research the vaccines themselves. How do vaccines work to protect us? What are the different types?

Unfortunately, we found that when we wrote that all out for you, it was mind numbing in its dryness. So, we looked for a visual and we found this video. It seems a little simple, we realize, but it does a really great job of explaining the very basics of how vaccines work.

If you have older children who are just getting vaccinated, we recommend The History of Vaccines website as a place to further your research with your children. For some children, getting shots can be a very traumatic experience. There are ways to make that experience less traumatic; teaching them about the science behind vaccines is just one way.


How Vaccines Work from Immunize For Good on Vimeo.

It is amazing how a simple vaccine can create years of immunity. Here’s how it works.

Vaccines protect your child from disease by allowing their body to perform a “practice run” in protecting itself against germs. So, if and when the real version of the disease appears, their body has already built the defenses it needs to stay healthy.

Whenever your child becomes sick their body makes infection-fighting antibodies. Once he or she recovers, these antibodies serve as “watchmen” for that particular disease and remain prepared to fight disease should it reappear. Vaccines trigger the same immune response as when the body encounters a disease, without causing illness.

If left totally to chance, your child’s first exposure to a disease may be from a germ too strong for their tiny body to fight. Before we had vaccines, many kids were hospitalized or died as a result of infectious diseases. The same germs exist today, but parents now have the ability and choice to protect their children.

How Vaccines Are Made

You already know that vaccines protect kids against severe and life-threatening disease, but you may not know exactly how vaccines are made to give your child a healthy defense.

Vaccines are made using the disease-causing virus or bacteria, but in a form that will not harm your child. Instead, the weakened, killed, or partial virus or bacteria prompts your baby’s immune system to develop antibodies, or defenders, against the disease.

Once it is determined how the virus and bacteria will be modified, vaccines are created through a general 3-step process:

  1. The antigen is generated. Viruses are grown in primary cells (e.g. chicken eggs for the influenza vaccine), or on continuous cell lines (e.g. human cultured cells for hepatitis b vaccine); bacteria is grown in bioreactors (e.g. Hib vaccine).
  2. The antigen is isolated from the cells used to create it.
  3. The actual vaccine is made by adding adjuvant*, stabilizers and preservatives. Adjuvants increase immune response of the antigen; stabilizers increase the vaccine’s storage life; and preservatives allow for the use of multi-dose vials.


*Adjuvants are often used to modify or augment the effects of a vaccine by stimulating the immune system to respond to the vaccine more vigorously. A common adjuvant is aluminum.

It is important to remember that vaccines undergo rigorous safety testing prior to Food and Drug Administration (FDA) approval and are continually monitored for safety. The vaccine production process involves several vaccine manufacturer-funded testing phases over many years to ensure that it is safe to administer. The vaccines are also studied to be administered in groups, to work together to protect your child.

View this infographic from the Centers for Disease Control and Prevention (CDC) to learn more about the journey of your child’s vaccine. You can also check out our page on vaccine ingredients.


Antigen: Any substance that causes the immune system to produce antibodies against it. Antigens include foreign substances (chemicals, virus, pollen, bacteria), or toxins within the body (bacteria toxins, tissue).

Pathogen: An agent that causes disease, such as a living microorganism (e.g. bacteria).

Antibody: Y-shaped proteins on the surface of B-cells that are secreted into blood in response to an antigenic stimulus that neutralizes the antigen by binding to it.

Source: Immunize for Good – How Vaccines are Made © Colorado Children’s Immunization Coalition