Vaccination is a powerful method for inducing humoral and cellular adaptive immune responses with the aim of controlling bacterial and viral infections and tumor growth as well. Vaccines are given to boost the immune system and prevent life-threatening diseases. It is a clinical application of immunization that is designed to artificially help your body to defend itself.
Although inoculation against smallpox was practiced nearly 2000 years ago in China and India, the credit to ushering the modern concept of vaccination goes to Edward Jenner, a British physician. He introduced the concept of vaccination in 1796 by inoculating patients against smallpox. By the year 1900, there were two human virus vaccines against smallpox and rabies, and three bacterial vaccines against typhoid, cholera, and plague.
Principle of vaccinations
Vaccination induces the host (healthy body) to build a primary response against the epitopes of the modified immunogen and generate large numbers of memory B and T cells. In a person not administered with any vaccinations, these memory B and T cells are present in relatively low numbers when the pathogen is encountered for the first time. Only the primary response system mounts against the pathogen, and as a result, the individual becomes sick until anti-bodies come into the picture for attacking the pathogen.
Here is how vaccines prepare your body to fight infections:
- They expose you to a very small and safe amount of viruses or bacteria that have been weakened or killed
- Your immune system learns to recognize and attack the infection when you are exposed to the same later on in life
- When the infection enters your body in the future, you may not become ill or develop a milder infection
Need for vaccination
Only until a few weeks after birth, babies develop natural protection from germs that cause diseases. This is passed through the placenta from the mother. This natural protection wears away in due course of time. Vaccines strengthen and equip the immune system to recognize and fight many diseases like tetanus, diphtheria, mumps, measles, and polio.
Types of vaccination
There are mainly four types of vaccines available:
Live virus vaccines: This type uses weakened forms of the virus for creating the vaccine. The vaccines used to treat measles, mumps, rubella (MMR), and varicella (chickenpox) are examples of this category.
Killed (or inactivated) vaccines: These vaccines are made from protein or other small components taken from virus or bacteria. The whooping cough vaccine is an example of this type.
Toxoid vaccines: These vaccines are made up of a toxin or a chemical made by the virus or bacteria. After you are administered with this type of vaccine, your body becomes immune to the harmful effects of the infection rather than the infection itself. Tetanus and diphtheria vaccines fall under this category.
Biosynthetic vaccines: These vaccines contain man-made substances that are similar to a bacteria or virus. Vaccination against Hepatitis B is an example of this type.
Importance of vaccination
Every year, vaccines prevent more than 2.5 million child deaths across the world. A vaccination program with the currently available vaccines can further prevent around 2 million child deaths. Here is why vaccines are vital for health:
- Vaccines promote better health: Vaccines help healthy people maintain their health and eliminate any major growth impeding infection or disease
- Vaccines have a wide reach: They protect individuals, communities, and an entire population of a country
- Vaccines have a rapid impact: The impact of vaccinations on communities and larger populations is almost immediate
- Vaccines can save lives: Vaccination programs are considered a cost-effective way of advancing global health and welfare.
Vaccination is a significant and progressive step in public health achievements in the history. Vaccinations that are part of a national immunization program are considered safe and effective.
