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Human Diseases Caused by Viruses

When a cell is infected with a virus several effects may be seen. Many viruses cause no harm or disease whatsoever. However, some viruses may attack certain cells and multiply within them.

9 Jan 2010

Virus Infection in Other Species

Viruses may infect all cells and each cellular organism has its own specific range of viruses that often infect only that species. Some viruses in addition can replicate only in cells that have been taken over by other viruses. These are called satellites or parasites of other viruses.

9 Jan 2010

Virus Microbiology

Viruses are the smallest obligate intracellular parasites that require living host cells in order to multiply and being alive. Viruses can infect any type of cell, ranging from human cells to protozoa.

9 Jan 2010

Virus Origins

Viruses have been referred to since ancient times. However, the exact origin of these tiny organisms that carry only the genetic information in a protein coat is still unknown.

9 Jan 2010

Virus History

Viruses have existed as long as life has been on earth.

9 Jan 2010

Vaccine Delivery

Once manufactured in large amounts, actual vaccine delivery and administration are of prime importance for it to be successful in preventing the ailment. Vaccine administration has been traditionally via injections but several new methods of vaccine delivery are also being explored these days. These new methods are hoped to improve compliance of the general population, ease administration and help in larger coverage.

9 Jan 2010

Vaccine Excipients

Vaccines are composed of the antigen preparation as well as some other ingredients. These serve to enhance the immune reaction to the vaccine (adjuvants), stabilize and prolong the shelf-life of the vaccine (stabilizers) and preserve the vaccine components (preservatives). These are termed excipients of the vaccine.

9 Jan 2010

Vaccine Production

Vaccine production has several stages. First, the antigen itself is generated. Viruses are grown either on primary cells such as chicken eggs (''e.g.'', for influenza), or on continuous cell lines such as cultured human cells (''e.g.'', for hepatitis A). Bacteria are grown in bioreactors (''e.g.'', ''Haemophilus influenzae'' type b).

9 Jan 2010

Vaccine Effectiveness

Vaccines help the body remember a microorganism to be able to fight it off when the need comes. However, vaccines are not fool proof and do not guarantee complete protection from a disease.

9 Jan 2010

Vaccine Schedule

Vaccines need to be administered at particular designated time in life to prevent the infection. For maximum effectiveness children are recommended to receive vaccinations as soon as their immune systems are sufficiently developed to respond to the components of the vaccines. Additional booster shots are required to teach the body fully to deal with the infection later in life. This requirement has led to the development of complex vaccination schedules.

9 Jan 2010

Vaccine Immunity

The immune system of the body functions to protect it against invasion by germs and microbes. When an individual is vaccinated against a disease or an infection, his or her immune system is prepared to fight the infection.

9 Jan 2010

Vaccine History

Vaccines have been found to be the most successful and cost effective public health measures that prevent disease and save lives. This is particularly true among children all over the world. Over the last half of the 20th century, diseases that were once all too common became rare in the developed world, due primarily to widespread immunization. Hundreds of millions of lives have been saved and billions of dollars in public health expenditures have been saved with widespread vaccinations.

9 Jan 2010