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Published on Mar 09, 2022 and last reviewed on Jun 23, 2022   -  6 min read


Immunization plays a vital role in protecting ourselves from various infectious diseases. Read the article below to know more about immunization.


What Does Immunization Mean?

The process of giving a vaccine to a person to provide protection from certain infectious diseases is called immunization or vaccination. Vaccines contain a small amount of genetically modified, weakened, or killed virus or bacteria or protein bits that mimic the virus to prevent infections caused by that same microorganism. This protection or immunity that the person gets through immunization is similar to what they get from the disease. But instead of acquiring immunity after contracting the disease, people can develop immunity through vaccines. This is why vaccines are considered a powerful medicine. While vaccines are mostly injected into the body, some are given orally (through the mouth) or nasally (through the nose).

How Do Vaccines Impact the Immune System?

Immunization helps save millions of lives every year. Vaccines work along with the body’s natural defense system and reduce the risk of getting an infection. When a person receives a vaccine, their immune system responds, resulting in the production of antibodies to that particular pathogen or enhancing immunity by some other method. After getting vaccinated, if a person is again exposed to the actual infection-causing pathogen, the immune system is already ready to fight it off, preventing the onset of a disease or reducing its severity.

As of now, we have vaccines for more than 20 life-threatening diseases such as diphtheria, pertussis, tetanus, measles, and influenza, which prevent almost three million deaths each year from infections. It is a key component of primary health care and one of the most effective ways of preventing and controlling infectious disease outbreaks. This is why as many people as possible need to get vaccinated. Immunization is essential to protect an individual and the entire society through herd immunity.

Why Is Immunization Necessary for Children?

The importance of getting our children vaccinated or immunized are:

  1. It protects children from severe illnesses or complications, such as amputation, paralysis, hearing loss, brain damage, convulsions, and death.

  2. Smallpox, measles, whooping cough, and mumps might seem like illnesses prevalent in the 19th century. But even now, more individuals get exposed to these infections, especially in schools and colleges, where large groups of people are present in a confined space.

  3. If not vaccinated, children can spread potentially fatal infections to other younger children or older adults with weakened immune systems.

  4. Immunization prevents pain and discomfort caused by such infectious diseases.

  5. Vaccines have helped eliminate various diseases that were fatal or severely disabled people a few years ago, such as smallpox and polio.

  6. Vaccines cost much less than getting treated.

  7. Immunizations prevent epidemics or outbreaks by developing herd immunity.

  8. Vaccines can save our lives. Hepatitis B can damage the liver and cause liver failure. HPV (human papilloma virus) can cause several types of cancer. Vaccines against these infections can help in preventing their occurrence.

Why Is Immunization Significant for Adults?

These vaccinations protect not only children but also adults. Vaccines against hepatitis B and tetanus in childhood are more helpful when we grow up. Chickenpox can result in more severe complications in adults than in kids. Adult vaccinations are often overlooked, and people do not know the importance of getting vaccinated as they age. Adults need to be vaccinated for a wide range of diseases like swine flu, tetanus, typhoid, hepatitis, and pneumonia. Adult vaccines commonly used are against hepatitis A and B, rabies, HPV, pneumococcal meningitis, meningococcal meningitis, and tetanus.

What Is the Importance of Travel Immunization?

While traveling to countries where certain infectious diseases are prevalent, it is crucial to take vaccines. For example, one needs to take yellow fever vaccination while traveling to African countries, and vaccinations against tuberculosis, meningococcal meningitis, and typhoid are required if you travel to European countries and the United States.

How Do Vaccinations Work?

Our immune system, composed of different types of cells, defends pathogens that enter the body. The cells in the immune system fight and get rid of the invading harmful pathogens. But, for them to get activated, they have to identify that the invaders are dangerous. This is where vaccinations come into play. Vaccines teach our bodies to recognize new diseases. They stimulate the body to produce antibodies against pathogenic antigens. The immune cells are also trained to remember the types of antigens that cause infection, which allows for a quick response to the disease when needed.

What Are the Types of Vaccines?

Safe versions of diseases are introduced in the body as vaccines, which can be:

  1. Subunit, Conjugate, Recombinant, Polysaccharide Vaccines - Contain a sugar or protein part of the pathogen.

  2. Killed (Inactivated) Vaccines - Has inactivated or dead pathogen.

  3. Live Virus Vaccines - Contains a weakened pathogen.

  4. Toxoid Vaccines - Possesses a toxin made by the pathogen.

What Are the Types of Immunization?

The protection obtained from antibodies can be achieved in two different ways:

1) Active Immunization - It is the type of immunity where the body triggers the production of antibodies against antigens on its own. This can be achieved after an infection or through vaccinations, and it provides long-term protection against diseases.

2) Passive Immunization - It is when antibodies are directly introduced into the body instead of the body producing them. It only provides short-term protection against diseases. Such immunity is transmitted from mother to child during delivery and breastfeeding or achieved by injecting immunoglobulins.

What Are the Side Effects of Vaccination?

Most people do not have any side effects, while some experience the following symptoms after getting vaccinated:

What Are Some Commonly Used Vaccines?

Early Childhood Vaccines:

  1. Inactivated poliovirus vaccine (IPV).

  2. MMR (measles, mumps, and rubella) vaccine.

  3. Hepatitis B vaccine.

  4. Pneumococcal conjugate vaccine (PCV).

  5. Varicella vaccine (chickenpox).

  6. DTaP (diphtheria, tetanus, and pertussis) vaccine.

  7. Haemophilus influenzae type B vaccine (Hib).

  8. Rotavirus vaccine.

  9. Influenza vaccine (every six months).

Mid Childhood Vaccines:

  1. Varicella vaccine (chickenpox).

  2. Hepatitis A vaccine.

  3. MMR (measles, mumps, and rubella) vaccine.

  4. Influenza vaccine (every year).

Young Adult Vaccines:

  1. HPV (human papillomavirus) vaccine.

  2. Tdap (tetanus, diphtheria, pertussis) booster.

  3. Influenza vaccine (every year).

  4. Meningococcal vaccine.

Adult Vaccines:

Apart from these, your doctor might also suggest other vaccinations based on your health, sexual orientation, hobbies, and other factors. After the COVID pandemic, COVID vaccinations are now being administered to people all around the world.

When Is Vaccination Contraindicated?

AIDS (acquired immunodeficiency syndrome) patients and people with cancer, and others with a weakened immune system should consult their doctor before getting vaccinated. Individuals on chemotherapy or immunosuppressant drugs can also have a weakened immune system. People with some allergies might not be able to get some vaccines, such as someone with gelatin or Neomycin allergy can develop a severe allergic reaction to the MMR and varicella vaccines.


Vaccinations are a prime tool needed for protection against several infectious diseases. Getting the vaccination at the right turn can help in reducing the disease severity and preventing disease contraction. This is more true in this pandemic, where the emergence of the COVID vaccines is the only hope to curtail the spread of the COVID-19. Therefore, it is essential to get a new shot or update your vaccination schedule whenever the situation prompts you to do so, like if you are traveling or at that time of the year when seasonal infections might occur.

For more information on immunizations, consult a doctor online now.


Last reviewed at:
23 Jun 2022  -  6 min read




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