What Is the Difference Between Immunization and Vaccination?

The terms immunization, vaccination, and inoculation are often used interchangeably, but the terms technically have slightly different definitions.

Girl getting vaccine at the doctor
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Immunity and Immunization

According to the World Health Organization (WHO), "immunization is the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine. Vaccines stimulate the body’s own immune system to protect the person against subsequent infection or disease."

A person becomes immune to a disease when the body has been exposed to it either through illness or vaccination. The immune system develops antibodies to the disease so that it cannot make you sick again.

Immunization describes the actual changes your body goes through after receiving a vaccine.

Vaccines and Vaccination

The U.S. Centers for Disease Control and Prevention (CDC) defines a vaccine as "a product that stimulates a person’s immune system to produce immunity to a specific disease, protecting the person from that disease. Vaccines are usually administered through needle injections, but can also be administered by mouth or sprayed into the nose."

Vaccination is the process of getting a vaccine into the body or "the act of introducing a vaccine into the body to produce immunity to a specific disease." A vaccine is what initiates the immunization process.


The definition of inoculation is "to give a person or animal a vaccine—a substance to prevent a disease." Inoculation is simply the process of giving a person a vaccine.

What Vaccines Do and Why

Vaccination or immunization is a process we use to protect people from potentially deadly diseases. Diseases that used to kill millions of people each year can now be prevented through vaccination. 

When you get a vaccine or immunization, the body "sees" the germs that cause the disease and develops protective antibodies. Once your body contains these antibodies, it will be able to fight off the germs if you are ever exposed to them and help prevent you from getting sick.

Sometimes this immunity wears off over time, which means additional vaccines may be needed later in life. When enough people in a community are vaccinated, it provides protection to everyone, even those that have not been vaccinated, through a process called community immunity or "herd immunity."

If the majority of people in a community are immune to a disease through immunization, it is unlikely to spread and affect anyone in the community like it would if people were not vaccinated.

This is how we have managed to eradicate or nearly eradicate several diseases that used to claim the lives of millions of people each year. When diseases aren't able to spread and make people sick, they die out.

Vaccine Schedules

Many parents are overwhelmed at the number of vaccines that are recommended for their babies starting just after birth. It may seem like it's too much to give an infant three or four shots at a time every couple of months during the first year of his life. However, that first year is when babies are most vulnerable to these diseases.

The vaccine schedule put out by the CDC has repeatedly been proven safe and effective at protecting children from those diseases that do still exist in our communities.

If a young child gets a disease such as pertussis (whooping cough), hepatitis B, or meningitis, the chance that it will claim their life is high.

There are some vaccines that are recommended for adults as well. The protective immunity that we get from some vaccines during childhood wanes during adulthood, so booster vaccines are needed. Additionally, there are some diseases that are more likely to affect adults, so they are recommended at different times during our lives.

A Word From Verywell

Vaccines, immunizations, and inoculations are all essentially a part of the same process. Medical professionals may use them in slightly different ways but to the general public, they are a way to prevent diseases without getting sick. Whether they are administered by injection, nasal spray, or orally, vaccines keep us healthy and save lives.

If you have questions or concerns about the need for vaccines for yourself or your children, talk to your healthcare provider. The benefits far outweigh the risks for a majority of people and they have quite literally changed the face of health throughout the world.

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Article Sources
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  2. Centers for Disease Control and Prevention. Immunization: The basics. Updated May 16, 2018.

  3. Greenwood B. The contribution of vaccination to global health: past, present and future. Philos Trans R Soc Lond, B, Biol Sci. 2014;369(1645):20130433. doi:10.1098/rstb.2013.0433

  4. Kim TH, Johnstone J, Loeb M. Vaccine herd effect. Scand J Infect Dis. 2011;43(9):683-9. doi:10.3109/00365548.2011.582247

  5. Centers for Disease Control and Prevention. Multiple vaccines at once. Updated August 14, 2020.

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