Medical terms like “Immunization,” “Vaccination” “Vaccine” and “Inoculation” are often used interchangeably. However, there are some technical differences between them that are worth noting. Using them correctly will help you better communicate with your physician or your child’s pediatrician.

What Are Vaccinations & Immunizations?

The World Health Organization is a global medical institution that helps standardize many terms and offer medical recommendations. They define the words “Vaccination” and “Immunization” as:

A vaccination uses an administered substance to stimulate the body’s own immune system to help protect the individual against subsequent infections or related diseases. The substance often contains part of the pathogen, such as a cell membrane protein or DNA.
The process of immunization makes the individual immune or resistant to an infectious disease by the administration of a vaccine or exposure to an illness. This means the person becomes immune to a disease when the body is exposed to a specific pathogen, and the immune system produces key antibodies to fight it. Immunization describes the actual immunological changes that the human body typically undergoes after coming in contact with a foreign substance. Therefore, the process of becoming immune can come via a scheduled vaccination or by exposure to a natural infection.

Is There A Difference Between Antibodies From Vaccines & From Natural Infection?

A vaccine essentially stimulates the body to rapidly develop protective antibodies against a pathogenic infection that the immune system encounters. The antibodies from a natural infection develop after the person has been exposed to the pathogen. But they are often the same antibodies. It takes time for these antibodies to develop. In some individuals with a compromised immune system, the time it takes to produce effective antibodies can be prolonged.

How Long Do Antibodies Last After A Vaccine?

This varies by the type of pathogen and the individual’s immune system. Some vaccinations confer immunities that last for years, whereas in others the person might only enjoy the benefits of active antibodies for 6 to 12 months. But even if antibody levels fall, you may still be protected. The immune system produces cells with “memory”; if reexposed to the pathogen, the “memory” cells (lymphocytes) can rapidly produce new antibodies to protect the individual.

What Is The Difference Between An Inoculation & Vaccination?

The Centers for Disease Control and Prevention (CDC) in the United States 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.”

The term inoculation means “the act of introducing a vaccine into a person’s body.” This can be done in several ways. The majority of vaccines are administered via needle injection, though some can be administered orally, or sprayed directly into a nostril. Most children prefer the “non injection” types, though unfortunately, there are few of these. A nasal spray form of the flu vaccine and an oral form of a vaccine to prevent rotavirus (a serious gastrointestinal infection) are examples.

In summary, immunization is the process whereby a person is inoculated (inject, sniff, drink) with a vaccine (substance that stimulates you to make antibodies) to produce immunity (protection from the disease).

What Do Vaccines Do?

Vaccines and immunization are designed to protect individuals from target pathogens that cause potentially deadly diseases. These include historically dangerous conditions such as polio, influenza, and coronavirus that cause health crises on a pandemic or world wide scale.
When a vaccine is administered it triggers your immune system to recognize the substance as harmful, and then to produce antibodies that the body specifically uses to target that disease and only that particular disease.This is different than other immune responses which target already infected cells and kill them before the virus or bacteria can replicate inside the cell and spread.

Vaccines develop an acquired or adaptive immune response that not only attacks and neutralizes the specific pathogen, but also produces special memory cells to trigger a rapid antibody response if you are exposed to that same pathogen again in the future. In this way vaccines dramatically reduce the risk of developing symptoms again. Even in the case of significant exposure to a strong pathogen, your symptoms might be very mild as the body quickly responds by producing more antibodies.

How Long Does Immunization Last?

The time you remain immune to a pathogen can vary by the vaccine, as well as the pathogen in question. To protect against most pathogens, booster vaccinations are needed to maintain a functional level of immunity.

An example of this is tetanus. In early childhood, infants receive several doses of tetanus vaccine to initiate immunity. Their immune systems are not as effective as older children and adults, hence the need for multiple doses. Then boosters need to be administered afterward to preserve immunity to this serious illness.

What Is Herd Immunity?

The term “Herd Immunity” refers to a population where a significant number of individuals are vaccinated or immunized via previous exposure. This safeguards unvaccinated individuals from getting the disease because the disease presence is low in the surrounding protected population.

Herd immunity is the most effective way that public health officials have for eradicating or virtually eliminating a certain disease. This includes conditions like polio, diphtheria, and flu that once cost millions of lives.

But herd immunity is not flawless. If a pathogen is very contagious, it can cause disease even when herd immunity is relatively high. This is the case with measles, which still causes yearly outbreaks in the United States. That is why it is so important for all of us to keep up with recommended vaccines.

Should I Worry About Vaccine Side Effects

Though no form of treatment is entirely without risk, the vaccines recommended by the CDC and the American Academy of Pediatrics are very safe. Most cause no or only mild adverse reactions such as:

  • Discomfort, swelling, or a rash at the injection site
  • A short-lived low-grade fever
  • Headache
  • Gastrointestinal discomfort

If you experience any of these symptoms after receiving a vaccine, you should consult your physician. In most of these cases, simple rest, proper hydration and occasional acetaminophen are all that’s needed until the minor side effects subside. Rarely, more serious side effects may occur.
Vaccines are extensively tested before licensure. Then, after a vaccine is licensed for administration by the FDA, vaccine side effects are carefully monitored. This led to the removal of a vaccine called RotaShield in 1999, when the Advisory Committee on Immunization Practices (ACIP) of the CDC voted on October ninth of that year to no longer recommend its use because of an association between the vaccine and intussusception (the inversion of one portion of the intestine within another). Overnight, Wyeth-Ayerst, the manufacturer of RotaShield, lost millions of dollars as its vaccine was pulled from the shelves of pharmacies, hospitals, and doctors’ offices.

Another example of how closely the vaccine program is monitored is the recent “pause” in administration of the Johnson and Johnson covid vaccine. Though the likelihood of developing a serious clotting disorder is extremely rare (about one per million doses), the ACIP paused administration pending further study of the problem. How rare is this side effect? You could receive the vaccine every day for over 3,000 years with only one chance of having the reaction. That is rare!

Some criticized the CDC for pausing administration under these circumstances, but their action proves that someone is keeping a close eye on the vaccine program.

Childhood Vaccination Schedules

The Centers for Disease Control and Prevention recommend a staggered battery of scheduled vaccines for children under the age of 18, as well as periodic boosters for adults.

The CDC’s vaccination schedule has been proven safe and effective at protecting children from common diseases as well as helping them stay healthy well into their adult life. This includes vaccinations for dangerous diseases such as pertussis (whooping cough), hepatitis B, and meningococcal meningitis as well as tetanus.

Vaccines like Zostavax and Shingrix are often recommended for older adults to help prevent shingles. An annual flu shot can also help prevent influenza and flu-like complications.