Vaccines are mainly responsible for the prevention of diseases. They are biological preparations used to heighten someone’s immunity towards a certain disease. Vaccines are made up of weakened or killed forms of a virus.
Types of vaccines
Killed vaccines contain dead microorganisms which have been killed with heat or chemicals to make them harmless. Some examples are vaccines against flu, cholera, bubonic plague, polio, and hepatitis A.
Attenuated vaccines contain live, weakened microorganisms. They have had their virulent properties disabled. Examples include vaccines against : yellow feaver, measles, rubella, mumps, and typhoid.
Toxoids are inactivated toxic compounds in cases where these (rather than the micro-organism itself) cause illness. Examples include vaccines for tetanus and dyptheria.
Subunit vaccines are those vaccines that contain only a part of a microorganism rather than the whole thing. This is because only that part is require for the body to trigger and immune response. An example would be the vaccine against hepatitis B.
Vaccines can also be designed to be a single target virus killers or target multiple viruses at once. A monovalent vaccines will immunize against a signle organism, while a multivalent vaccines will immunize against two or more strains of an microorganism.
When a person is vaccinated, its immune system will remember the virus. When the real virus come along it is recognized as a foreign agent and it is destroyed. The real viruses are recognized by their protein coats. Then the body is ready to respond in one of two ways. It either neutralizes the threat before it reaches the cells, or it will destroy infected cell before the disease can spread.
The eradication of smallpox, one of the most contagius and deadly disease known to man has been attributed to vaccines. Diseases that were very common before such as rubella, polio, measles, mumps, chickenpox and typhoid have now been brought under control by vaccines.
As soon as a childs immune system is developed enough to respond , vaccination is recommended. A complex vaccination schedule has been developed in the Unites States, which requires up to 24 vaccinations by age two. Most other vaccines such as measles, tetanus, influenza and pneumonia are recommended later and throughout life, especially influenza in the elderly which is deadly to the group.
Because sometime a persons immune system simply does not respond right or at all, vaccines might not be effective in some cases. This may be caused by the lack of and or antibodies not working properly. The efficiency of a vaccines depends on: the disease itself, the strain of vaccine, whether the timetable for vaccinations has been followed, some people not responding to a vaccine even if it was done properly.
If a person does develop the disease he was vaccinated against, it is most likely for the disease to be milder than it would be without vaccination.
|body, contain, disease, immune, killed, organism, vaccine, vaccines, virus|