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Vaccination Basics

The Benefits of Vaccination

The body’s immune system helps protect against pathogens that cause infection. Most of the time, it’s an efficient system. It either keeps microorganisms out or tracks them down and gets rid of them. However, some pathogens can overwhelm the immune system.  When this happens, it can cause serious illness.

The pathogens most likely to cause problems are the ones the body doesn’t recognize. Vaccination is a way to "teach" the immune system how to recognize and eliminate an organism. That way, your body is prepared if you are ever exposed.

Vaccinations are an important form of primary prevention. That means they can protect people from getting sick. Vaccinations have allowed us to control diseases that once threatened many lives, such as:

  • measles
  • polio
  • tetanus
  • whooping cough

It’s important that as many people as possible get vaccinated. Vaccination doesn’t just protect individuals. When enough people are vaccinated, it helps protect society. This occurs through herd immunity. Widespread vaccinations make it less likely that a susceptible person will come into contact with a disease.

How Does Vaccination Work?

A healthy immune system defends against invaders. The immune system is composed of several types of cells. These cells defend against and remove harmful pathogens. However, they have to recognize that an invader is dangerous.

Vaccination teaches the body to recognize new diseases. It stimulates the body to make antibodies. It also primes immune cells to remember the infection. That allows for a faster response to the disease in the future.

Vaccines work by exposing you to a safe version of a disease. This can take the form of:

  • a protein or sugar from the surface of a pathogen
  • a dead or inactivated bacterium
  • a virus-like particle that is not infectious
  • a weakened pathogen

When the body responds to the vaccine, it builds an adaptive immune response. This helps equip the body to fight off an actual infection.

Vaccines are usually given by injection. Most vaccines contain two parts. The first is the antigen. This is the piece of the disease your body must learn to recognize. The second is the adjuvant. The adjuvant sends a danger signal to your body. It tells it to respond to the antigen as an infection. This helps you develop immunity.

Active vs. Passive Immunity

Antibodies help the body recognize diseases. Protection from antibodies can be achieved in two different ways.

Active immunization teaches the body to recognize a pathogen. It stimulates long-term protection against a disease. Active immunity can occur after an infection (natural immunity). It can also occur through vaccination (artificial immunity). 

Passive immunization provides short-term protection against a disease. It occurs when someone receives antibodies instead of making their own. Passive immunity is transmitted naturally from mother to child during birth and breast-feeding. It can also be achieved artificially through the injection of immune globulins. These are antibody-containing blood products. 

Why People Don’t Get Vaccinated

In recent years, vaccine opponents have challenged their safety and effectiveness. However, their arguments have generally been flawed. Vaccination is a very safe way to prevent disease. There is no good evidence that vaccination can cause autism. However, there is a lot of evidence that vaccines can prevent serious disease and death.

Not all people avoid vaccinations because of safety concerns. Some simply don’t know that they should be vaccinated. For example, people should get the flu vaccine every winter. However, according to the Centers for Disease Control and Prevention (CDC), around 60 percent of Americans don’t get the annual flu shot. Many have no idea they should.

It’s important to talk to your doctor about what vaccines you need. Avoiding vaccination puts you at risk of serious disease. It can lead to costly doctor’s visits and hospital fees.

What If We Stopped Vaccinations?

Vaccines can reduce disease. For example, vaccination helped to eliminate polio from the Western hemisphere. According to the CDC, polio used to paralyze 13,000 to 20,000 people each year in the United States. Vaccination has also reduced the number of measles infections by more than 99 percent.

Ending vaccination could be very dangerous. Even today, around the world, many vaccine-preventable deaths still occur. This is because vaccines are not available to everyone. One of the missions of the World Health Organization (WHO) is to increase vaccine availability. The WHO estimates that, each year, over 1 million children die of diseases that could be preventable by vaccine.

Content licensed from:

Written by: Amy Boulanger
Medically reviewed on: Nov 06, 2014: Brenda B. Spriggs, MD, MPH, MBA

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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