Antivirals

=Antivirals =

What is a Virus? Viruses are "micro-organisms" that media type="youtube" key="Rpj0emEGShQ?fs=1" height="324" width="522" align="right"can survive by themselves (3). They come in different shapes and structures, with a central core conformed by either deoxyribosenucleic acid (DNA) or ribonucleic acid (RNA), that is surrounded by a coat made of tightly packet protein units known as capsomeres, which contains many protein molecules. For a virus to reproduce, it requires the help of a cell. What happens is that a virus penetrates a cell, and releases its genetic material (DNA or RNA) into the host cell's cytoplasm, thus taking control over the cell. By doing, the cell will then code to produce millions and millions of viruses that will spread and infect other healthy cells, which could terminally kill them or damage them. This is how the symptoms of a virus infection begin.

Some of the common diseases spread by viruses are:
 * Common Cold
 * Influenza
 * Herpes
 * HIV
 * Smallpox
 * Chickenpox

 Information about the common diseases were obtained from Medical News Today. (4)

Virus vs. Bacteria Many people commonly get confused between what a virus and a bacteria are, thinking that they are similar. However, there are big differences between the two:
 * = Virus ||= Bacteria ||
 * = No nucleus ||= Nucleus ||
 * = No cytoplasm ||= Cytoplasm ||
 * = Cannot carry the functions of life (feed, respire, excrete, grow) ||= Carries the functions of life ||
 * = Needs a cell to reproduce ||= Can reproduce by itself ||
 * = range from 20 - 250 nanometers long (2) ||= average of 1000 nanometers long (2) ||
 * = Surrounded by a protein coat ||= "Cell wall" (2) ||
 * = Antibiotics have no effect (1) ||= Antibiotics can kill bacterias (1) ||

<span style="color: #72acc2; display: block; font-family: 'Comic Sans MS',cursive; font-size: 120%; text-align: justify;">Because viruses don't perform the functions of life, it is thought that viruses are more like "mechanized bits of information, or robots", rather than a living thing (2). Unlike bacteria that are "one-celled living organisms" (2). However, one of the biggest difference between the two is the fact that most bacterias are "quite beneficial" and "harmless" (2). There are many of them inside the human body, that carry out different functions, such as helping digestion or preventing infections (2). For example, bacterias are now used as "probiotic dietary supplements", the 'good' bacterias. On the other side "all [viruses] are extremely harmful to humans" (1). Yet, that doesn't mean that bacterias are all good, some maybe hazardous. <span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 160%;">How to counter-attack viruses: Antivirals <span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 120%;">As mentioned before, bacteria can be treated with the use of antibiotics, however, it can't treat viruses. This is why viruses are considered to be more deadly. Many people believe that medicines can fully treat antiviral infections, when in reality, antiviral drugs "block certain steps in the messaging system, which disables the virus from reproducing", thus producing less viruses for the immune system to eliminate (5). Some antivirals have also been developed to "stimulate the immune system so that the body can fight the viruses itself" (6). So in other words, it is the body's immune system the one that does most of the job to kill the viruses, antivirals are just used to "reduce [...] symptoms, shorten the length of illness and potentially reduce the serious complications [...]" (7). In most cases, it isn't required to take antivirals, unless it is to relieve pain or fever, because the immune system should work fine in fighting the viruses.

<span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 120%;">Antivirals come in different forms, such as "capsule, tablet, liquid, ointment, and injectable forms" (6). A few examples of antivirals are:
 * <span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 120%;">acyclovir (Zovirax)
 * <span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 120%;">amantadine (Symmetrel, Symadine)
 * <span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 120%;">ganciclovir (Cytovene)
 * <span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 120%;"> valacyclovir (Valtrex)

<span style="color: #72acc2; font-family: 'Comic Sans MS',cursive;">Information on antiviral names and brands obtained from Health Publications (6)

<span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 120%;">First of all, antiviral drugs are a recent development of humans, who found out the "genetic sequences" of some viruses, which allowed them to identify proteins that took part of the virus' function (8). Because researcher found out about the genetic structure of viruses, they were able to develop drugs such as acyclovir to counter-attack colds caused by the herpes virus. Taking acyclovir as an example, its structure is very similar to deoxyguanosine, a building block of the virus' DNA. What acyclovir does is trick a viral enzyme into using it to build an infected DNA strand. By doing so, the new DNA strand no longer is infected or in other words, can be used to produce more viruses.



<span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 120%;">Another way in which antivirals may work is the way amantadine works. Amantadine is currently one of the drugs used to treat influenza. What it does is to prevent newly created viruses from coming out of the infected cell. As one can see, there are different ways in which antivirals work, but a draw back is that antivirals have specific viruses they attack, one antiviral may work with this virus, but not with the other one (5). What is worst, antivirals might not even work if the virus has propagated enough that many cells have already been infected or too many viruses have been produced (5). <span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 120%;">Finally, one last newly discovered way of stopping the production of viruses, is through the inhibition of enzymes. A recent investigation found out that "viruses make an enzyme called" protease (9). Protease is used to help grow the newly formed viruses (9). So researchers have found that by blocking the active sites with the help of a drug that can bind to it, the function of protease in the loop of virus fabrication would be stopped (9). Therefore, terminating the viral production (9).

D.7.3 Discuss the difficulties associated with solving the AIDS problem. (Kyung Min Kim)

<span style="color: #72acc2; font-family: 'Comic Sans MS',cursive; font-size: 160%;">Footnotes: 1. Difference Between Bacteria and Virus 2. Bacteria vs. Viruses 3. What is a Virus? 4. Medical News Today 5. eHow - How Antiviral Medicine Works 6. Health Publications 7. Public Health Agency of Canada 8. CBC News In Depth: Flu 9. Enzyme Studies Flu Attack Video Virus Image Acyclovir Image