What Is the Difference Between Immunization and Vaccination?

The terms immunization, vaccination, and inoculation are often used interchangeably, but the terms technically have different meanings. While the differences may seem semantic, using the terms correctly can help prevent misunderstandings between you and your healthcare provider.

Vaccination vs. Immunization

Verywell / Mayya Agapova

Vaccination vs. Immunization vs. Inoculation

According to the World Health Organization (WHO), vaccination and immunization are related, although one describes an action while the other describes a process.

By the WHO definition:

  • Vaccination employs vaccines to stimulate the body’s own immune system to protect a person against subsequent infection or disease.
  • Immunization is the process wherein a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine.

The Centers for Disease Control and Prevention (CDC) offers similar definitions:

  • Vaccination is the act of introducing a vaccine into the body to produce immunity to a specific disease.
  • Immunization is a process by which a person becomes protected against a disease through vaccination.

A person can become immune to a disease when the body is exposed to the disease-causing organism (pathogen) and develops antibodies to fight it. But in the modern lexicon, immunization almost always infers immunity by vaccination rather than by natural infection.

The term inoculation, meanwhile, is often used interchangeably with vaccination or immunization.

From a historical perspective, it describes the introduction of a substance into the body to confer protection. The term was first coined in the 18th century to describe variolation (the act of introducing a small amount of pus from someone with smallpox into the body of someone without it).

As with immunization, the term inoculation almost invariably infers the use of vaccines.

What Vaccines Do

Vaccination and immunization aim to protect people from potentially deadly diseases. Diseases that once killed millions, like polio and influenza, can now be prevented through vaccination. 

When you receive a vaccine, your immune system will recognize the substance as harmful and tailor-make antibodies designed to target that disease and that disease alone.

This is referred to as the acquired (or adaptive) immune response. The adaptive response not only attacks and neutralizes the specific pathogen but leaves behind memory cells to re-launch an attack should the pathogen return. Doing so reduces your risk of symptomatic illness should reinfection occur.

When enough people in a community are vaccinated, it can provide protection to everyone—even those who have not been vaccinated. It does so by reducing the number of people able to spread the infection within that community, a process referred to as herd immunity.

This is how public health officials have been able to eliminate (or nearly eliminate) diseases like polio, mumps, and measles, which once claimed millions of lives. When diseases aren't able to spread, they eventually die out.

Vaccine Timing and Durability of Immunization

Vaccination is needed to immunize against diseases that can do harm. This starts from the time of birth and continues into later life, and the timing is based on the general risk of a disease in a period of life.

Some parents are overwhelmed by the number of vaccines their child receives from the time of birth. But following the recommended schedule is important as vaccinations are timed to protect against specific diseases when a child is most vulnerable to them.

The vaccine schedule issued by the CDC has been proven safe and effective at protecting children from common diseases that still exist in many communities. Not getting vaccinated places a child at serious risk.

The chances of severe illness and death from pertussis (whooping cough), hepatitis B, or meningococcal meningitis are significantly higher in an unvaccinated child versus a vaccinated one.

There are also vaccines recommended for adults, such as the Shingrix vaccine used to prevent shingles.

Remember that it's immunization that ultimately confers immunity. In other words, though you may have been vaccinated against a certain disease in childhood, it's your level of immunization that determines how protected you are today.

The duration of immunity can vary by the vaccine, with some wearing off relatively quickly and others providing lasting protection.

In cases where immunity has begun to wane, revaccination or booster shots may be needed. Tetanus is one such example.

A Word From Verywell

Vaccination, immunization, and inoculation are all essentially a part of the same process: to keep you safe from diseases that might otherwise cause you harm. Whether administered by injection, nasal spray, or orally, vaccines afford protections that almost always outweigh the potential risks.

If you are unsure whether you need a vaccine (or if a vaccine is appropriate for you), speak with your healthcare provider or a qualified medical professional.

Frequently Asked Questions

  • What are the different kinds of vaccines?

    There are many different kinds of vaccines that include live-attenuated vaccines; inactivated vaccines; subunit, recombinant, polysaccharide, and conjugate vaccines; toxoid vaccines; mRNA vaccines; and viral vector vaccines. Depending on the type, the vaccine may use a weakened version of the germ that causes disease, a dead version of the germ, parts of the germ, a toxin that harms the germ, or genetic material to develop an immune response.

  • How does herd immunity work?

    Herd immunity helps keep entire communities safer from disease outbreaks because enough people are vaccinated and less likely to catch and spread the disease.

  • How do vaccines get FDA approval?

    Vaccines get FDA approval by undergoing a rigorous research, development, testing, and approval process. After research determines that the vaccine is necessary and can be tested, it starts in a lab with animal testing before human testing can begin. There are at least three phases of human testing for effectiveness and safety before a vaccine can move on to an approval process. Even after approval, vaccines are still monitored closely by the FDA.

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12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  8. Centers for Disease Control and Prevention. Multiple vaccines at once. Updated August 14, 2020.

  9. Centers for Disease Control and Prevention. Who should get diphtheria, tetanus, and whooping cough vaccines?. Updated December 17, 2018.

  10. Centers for Disease Control and Prevention. Ensuring the safety of vaccines in the United States. Updated June 27, 2018.

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