
A
vaccine is a medical preparation produced to improve immunity to a
particular disease. This is done by stimulating the production of
antibodies. Basically, a vaccine contains an agent that is similar to a
disease-causing microorganism and this is produced from weakened or killed
forms of the microbe or its toxins. The agent helps in stimulating the
body's immune system so that it can fight and destroy the foreign substance
in the body. Vaccines are of various types. The most common method of
administering vaccines is by injection, but some are given by mouth or nasal
spray.
How Vaccines Work?
There are at least two distinct effects on the
body as a result of the disease causing organisms . They are as follows:
- Sickness, displaying symptoms like nausea, vomiting, diarrhea, fever,
rash, and many others.
- The second effect is less obvious. This effect usually leads to
eventual recovery from the infection. The disease causing organism
produces an immune response in the infected host. As the response
increases in strength over time, the infectious agents decrease in
number until symptoms disappear and there is complete recovery.
This induction of the immune response occurs with the help of the "antigens",
which are the proteins contained in the disease causing organisms. The
resulting immune response includes the synthesis of proteins called "antibodies."
These antibodies bind to the disease causing organisms and lead to their
eventual destruction. As a result of immune response, "memory cells"
are produced. They remain in the blood stream ready to provide a quick
protective immune response against infections with the particular disease
causing agent which lead to their production. If such an infection occurs,
the memory cells respond so fast that the resulting immune response
immediately inactivate the disease causing agents, and symptoms are
prevented. This response is so fast that you are immune from infection.
Types of Vaccines
There are different types of vaccines use in
hospitals and health care centers. Certain vaccines contain micro-organisms
that have been destroyed or killed with chemicals or heat. Examples are the
cholera vaccine, influenza vaccine, polio vaccine,
hepatitis A
vaccine, and rabies vaccine. Some vaccines contain live, attenuated
microorganisms, used to treat viral diseases yellow fever, measles, mumps,
and typhoid. There are Toxoid vaccines produced from inactivated toxic
compounds that cause illness rather than the micro-organism. Examples of
toxoid-based vaccines include diphtheria and tetanus. There are protein
subunit vaccines, where a fragment of it can create an immune response. For
example, such vaccine is used in against
Hepatitis B virus.
Nowadays there are synthetic or experimental vaccines, which are composed
mainly or wholly of synthetic peptides, carbohydrates or antigens , instead
of inactivated or attenuated compounds from micro-organisms.
Depending on the various strategies used in the manufacturing of vaccines,
the various vaccines are classified as follows:
- ANTHRAX Vaccines
- DIPHTHERIA Vaccines
- HEPATITIS A Vaccines
- HEPATITIS B Vaccines
- HIB Vaccines
- HPV Vaccines
- INFLUENZA (Flu) Vaccines
- JAPANESE ENCEPHALITIS (JE)
- LYME DISEASE Vaccines
- MEASLES Vaccines
- MENINGOCOCCAL Vaccines
- MUMPS Vaccines
- PERTUSSIS Vaccines
- PNEUMOCOCCAL Vaccines
- POLIO Vaccines
- RABIES Vaccines
- ROTAVIRUS Vaccines
- RUBELLA Vaccines
- SHINGLES Vaccines
- SMALLPOX Vaccines
- SWINE FLU Vaccines
- TETANUS Vaccines
- TUBERCULOSIS (TB) Vaccines
- TYPHOID Vaccines
- CHICKENPOX (Varicella)
- YELLOW FEVER Vaccines