My name is Amanda and I am an undergrad Nursing student at Alverno College in Milwaukee, Wisconsin. For my Microbiology class I was assigned the topic of "antiviral drugs" to write a blog about. I decided that with the massive amounts of media coverage the Ebola epidemic is getting, I'd focus on antiviral drugs for the treatment of Ebola.
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Antiviral Drugs: Background
Antiviral drugs, unlike antibiotics, don't target the pathogen directly, but they aim to inhibit the growth and development of a virus (Tortora, Funke, Case, 2013). Because viruses multiply within our cells, they are very difficult to target without also harming our own cells. There are three major categories of antiviral drugs. The first category are nucleoside and nucleotide analogs which target the reverse transcriptase step of RNA viruses because it is not used in our DNA. The second category includes interferons. Cells that are infected with a virus will release a specific cytokine called interferons which help contain the virus and prevent it from spreading. Interferon antivirals stimulate the release of these interferons. The third major category of antiviral drugs are other enzyme inhibitors. These drugs target other enzymes within a virus to prevent it from developing.
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Why is Ebola difficult to Treat/Cure?
You have probably heard in the news that people currently infected with Ebola are "treated" by receiving intravenous fluids or just by receiving treatment to control their blood pressure and oxygen levels. Ebola is currently not treated with antiviral drugs because it is a relatively new and fast-evolving virus (Rettner, 2014). Because of how quickly it evolves and how many different strains there are, it's difficult to develop a "cure-all" for it. It's also very difficult to study because there are only a few laboratories in the world that have the capabilities to work with it. Also, since the Ebola virus targets humans' immune cells which causes our immune system to be overwhelmed and it literally causes our own immune system to attack our organs. This attack happens so quickly that it's incredibly difficult to study it long enough to figure out how to develop a drug to treat it.
Antivirals Being Studied
There is currently an antiviral drug called ZMapp that is being studied as a possible treatment for the Ebola virus. According to the CDC, ZMapp is still in the very early stages of study and has not yet been tested on humans (2014). Controlled, ethical, clinical studies need to be done in order to know if this antiviral drug is effective against the Ebola virus, and it's a very long and difficult process to begin performing those studies. ZMapp is basically a combination of several different antibodies that bind to the protein within the virus and stop it's development and reproduction.
Other than the company developing ZMapp, there are two other companies currently working towards developing another possible antiviral drug against ebola as well as a possible vaccine.
In Conclusion
Although rehydration therapies seem to have a high success rate in patients infected with Ebola virus in the United States, the virus obviously has a very high mortality rate in Africa. It is vitally important that an antiviral drug is developed and distributed to the communities that are most affected by this epidemic in order to control it and keep it from spreading further. The research and studies needed to develop these drugs is taking a very long time because the virus itself is difficult to study and it kills so quickly and so often that it's difficult to find survivors to study. Moving from animal to human studies in a laboratory setting raises obvious ethical concerns that need to be addressed in order to determine the drugs' effectiveness in human bodies to develop a treatment or cure for this virus.
References
Centers for Disease Control
and Prevention, (2014.) Questions and
answers on experimental treatments and vaccines for ebola. Retrieved from http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/qa-experimental-treatments.html
Rettner, R. (2014, June 23.)
Ebola virus: why isn’t there a cure? LiveScience.
Retrieved from http://www.livescience.com/46479-ebola-treatment-cure.html
Tortora, G., Funke, B., &
Case, C. (2013). Microbiology: an
introduction, 11th edition. Glenview, IL: Pearson Education,
Inc.
