One method of preventing disease-related infections is by vaccination.

Vaccination is simply making use of the original defense of your body to protect and strengthen your immune system. It is a method that has proven efficient and safe in playing a part in preparing the body for possible diseases before the body is even exposed to them.

Vaccination involves the process of introducing a weakened or inactive form of a virus or bacteria, or even just a small part of it, into the body to teach the immune system how to recognize as well as tackle that bacteria should it make its way into the body. Substances that contain these weak or inactive forms of viruses or bacteria are called Vaccine. A vaccine, is a trigger to your immune system. It helps the immune system to recognize the threat ( a bacteria or virus ) after the inactive form has been introduced and in turn, builds defenses against it.

Classification of vaccines 

1. Live attenuated vaccines : These vaccines contain a weakened form of the live virus. They mimic a natural infection, but without causing a full-blown illness. Examples of diseases with this kind of vaccine are: Measles, mumps, and rubella (MMR) vaccine, chickenpox vaccine.

2. Inactivated vaccines: These vaccines use a killed version of the virus or bacteria. While they can not replicate, they still effectively train the immune system.Examples  include: Flu vaccine, polio vaccine, salk vaccines.

3. Toxoid vaccines: Toxoid vaccines are produced by taking out a bacterial toxin and changing it chemically (usually with formaldehyde), to convert the toxin to a toxoid. Toxoid vaccines induce antibodies that target the toxins released from these bacteria to neutralize them.Vaccine examples: Diphtheria, tetanus.

4. Subunit vaccines : These vaccines contain only specific proteins or antigens from a virus or bacteria which would release an immune response against those specific parts of the bacteria or virus. Examples include: Hepatitis B vaccine and HPV vaccine.

5. Recombinant vaccines: Recombinant vaccines are vaccines made from a gene from the disease-causing pathogen. The gene extracted is inserted into a cell system capable of producing large amounts of the protein of interest. The protein produced can generate a protective immune response.Vaccine examples: Hepatitis B vaccine and HPV vaccine.

Modes of action of vaccine.

Here is a little guide to how vaccines work in the body.

1. Introduce the vaccine: A vaccine is given through a shot, mist, or drops. This activates the immune system as the body recognizes the weakened/inactive germ or parts of it in the vaccine as foreign.

2. Antibody production: The immune system creates proteins called antibodies specifically designed to fight that particular germ.

3. Memory T cells: The immune system also creates memory T cells that remember the germ whenever it decides to invade the body.

Modes of Vaccination Administration 

Vaccines can be administered in various ways to best suit the specific vaccine and the individual:

Intramuscular injection:  This is the most common method, where the vaccine is injected into a muscle, typically the arm or thigh. An example in children are: Diphtheria, tetanus, and acellular pertussis (DTaP). For Adults: Shingles vaccine (zoster)

Subcutaneous injection: The vaccine is injected just beneath the skin, often in the upper arm or abdomen. Examples in children: Varicella (chickenpox). In Adults, Hepatitis A vaccine

Oral administration: Some vaccines, like the rotavirus vaccine for children, are given by mouth. Examples include oral polio vaccine and cholera vaccine.

Nasal spray: This method is used for certain vaccines, like the flu vaccine mist, delivered directly into the nose.

Common vaccinations for children and adults.

Here are some examples of common childhood vaccines:

Hepatitis B (HepB): Protects against hepatitis B, a liver infection that can cause lifelong health problems.The first dose is usually administered to newborns within 24 hours of birth. The second dose is administered within the 1st and 2nd month. The third dose is administered between the 6th and 18th month.

Rotavirus (RV): Protects against rotavirus, a severe diarrhea illness that can lead to dehydration.
It can be administered in 3 doses after birth i.e at :
2 months old
4 months old
6 months old

Diphtheria, Tetanus, and Acellular Pertussis (DTaP): Protects against three serious diseases: diphtheria, tetanus, and pertussis (whooping cough).

First dose at 2 months
Second dose at 4 months 
Third dose at 6 months
Fourth dose at 15-18 months 
Fifth dose in-between ages 4-6years

Haemophilus influenzae type b (Hib): Protects against Hib, a bacteria that can cause meningitis, pneumonia, and ear infections.The first dose is typically given at 2 months of age. The second dose is usually administered at 4 months of age.The third dose is given at 6 months of age. Booster Dose is recommended between 15 and 18 months of age, with a minimum interval of 6 months since the third dose.

Pneumococcal conjugate (PCV13): Protects against serious infections caused by pneumococcus bacteria, such as pneumonia, meningitis, and ear infections.The first dose of PCV13 is typically given at 2 months of age.The second dose is usually administered at 4 months of age. And the third dose is given at 6 months of age. While a fourth dose is recommended between 12 and 15 months of age, with a minimum interval of at least 2 months since the third dose.

Inactivated poliovirus (IPV): IPV protects against polio, a crippling and potentially life-threatening disease. The first dose is administered at 2 months of age. The second Dose is usually administered at 4 months of age.The third Dose is given at 6-18 months of age. Fourth Dose (a booster dose) is recommended between 4 and 6 years of age.

Meningococcal: Protects against meningitis, a serious infection of the lining of the brain and spinal cord. There are different vaccines for different types of meningococcal bacteria and administration is dependent on the age of the child and risk factors.

Human papillomavirus (HPV): Protects against certain types of human papillomavirus (HPV) that can cause cervical cancer and other cancers. This vaccine is recommended for preteens at ages 11 or 12.

Measles, mumps, and Rubella (MMR): Protects against three contagious childhood diseases: measles, mumps, and rubella.

The Measles, Mumps, and Rubella (MMR) vaccine is administered to children in the United States according to a two-dose schedule: The first dose of the MMR vaccine is typically given between 12 and 15 months of age. While the second dose is recommended between 4 and 6 years of age.

For Adults 

COVID-19 vaccine: Everyone needs to stay up-to-date on COVID-19 vaccinations, including booster shots when recommended.

Flu vaccine (influenza): Yearly flu shots are recommended for everyone 6 months and older to help prevent seasonal flu.

Tdap vaccine (tetanus, diphtheria, and pertussis): A booster shot is recommended every 10 years to protect against tetanus, diphtheria, and whooping cough (pertussis)

Shingles vaccine (zoster): Recommended for all adults 50 years of age and older to help prevent shingles, a painful rash that can occur after having chickenpox.

Hepatitis B vaccine: Recommended for all adults up to age 59, and for some adults 60 years of age and older with known risk factors, to help prevent hepatitis B, a liver infection.

Pneumococcal vaccine: Recommended for all adults 65 years of age and older, and younger adults with certain health conditions, to help prevent pneumococcal disease, which can cause pneumonia, meningitis, and ear infections.

Importance of vaccination.

Without vaccines, we are susceptible to serious illness and disability from diseases like measles, meningitis, pneumonia, tetanus, and polio. Many of these diseases can be life-threatening. An estimate that childhood vaccines alone save over 4 million lives every year has been done by the World Health Organization (WHO)

With all we have discussed above, you see the need and importance of this vaccination. When you get vaccinated, you are not only protecting yourself, you are also protecting those around you.