Bringing You the Best

Chewing The Scientific Fat


Do We Finally Have Control of the Ebola Virus?

By Shelsie Delphin 8/5/2015

picture of vaccine and needle Diagram of herd immunity

     Great News! According to the WHO (World Health Organization), we are currently on the verge of an effective Ebola Vaccine. WHO Director-General Dr. Margret Chan states that the credit goes to the Guinean government, and to the people of the Guinean communities that participated. In 2014, as we remember, a huge outbreak occurred in Guinea and a few other West African countries, which caused great concern worldwide. For some time, extensive research has been ongoing to see if it possible to combat the deadly virus, which paved the way for some clinical trials. Clinical trials are experimental studies that are done to test the effectiveness of a medical strategy or treatment, in this case a vaccine. A vaccine, for those who have always wondered, is basically a weakened version of the virus that our body can create antibodies for and kill off. These antibodies last for about 75 years or so, and so grants you immunity for most of your life. Anyway, back to the good stuff, March 2015 marked the beginning of the Guinea Phase III trial, which was to test the Vesicular Stomatitis Virus-Ebola Virus vaccine (VSV-EBOV), (Developed by the Public Health Agency of Canada) for effectiveness against the Ebola Virus. Over 4000 close contacts of almost 100 Ebola patients voluntarily participated, that includes family members, neighbors, and co-workers. As alluded to, the method used to distribute the vaccine was something called ring vaccination, which is a disease control strategy where a vaccine is administered only to people in close contact with an infected patient. The objective of the trial was to determine whether the vaccine could protect the contacts who were vaccinated, and if vaccinating the contacts would create a buffer of protected individuals to prevent further spread of the infection. Fast-forward to today, the World Health Organization is reporting that the VSV-EBOV vaccine is highly effective against Ebola, and shows 100% efficacy in individuals treated. Granted the effectiveness of the vaccine, we aren't out of the woods yet, as the vaccine is yet to receive clearance for the general population. Thus, we have no "herd immunity", which is an indirect form of protection from an infectious disease when a large percentage of a population becomes immune to it, providing protection for individuals who are not immune. That is, it prevents the spread of the disease by limiting the amount of people it can infect, thereby protecting those who have not been vaccinated, as depicted to the right. Thankfully, the Guinean national regulatory authority and ethics review committee has allowed continuation of the trial. So, this is exciting news, and hopefully we will never have to worry about this Ebola strain again!

What is Ebola?

     Ebola Virus disease, also known as Ebola Hemorrhagic fever, is a rare deadly illness caused by one of the strains of the Ebola virus. There are 5 known strains classified in the genus Ebolavirus, family Filoviridae. It affects humans and also nonhuman primates (monkeys, chimpanzees, and gorillas). In 1976 two outbreaks occurred simultaneously, in Nzara, Sudan and Yambuku, in the Democratic Republic of Congo. The Latter occurred in a village near the Ebola River, from which the disease gets its name. The natural reservoir of Ebola virus has not yet been proven or identified, for that reason, how the virus first appears in a human at the onset of an outbreak is unknown. It is theorized that the virus' natural reservoirs are in fruit bats.

How Ebola is contracted

     Ebola is spread through direct contact with infected bodily fluids. That means that an infected person has touched another person's eyes nose, open cut or wound. An infected person with Ebola cannot spread it to other people until symptoms begin (that's an average of 8 to 10 days).

Diagram of ebola contraction

Symptoms & Treatment

Diagram of ebola symptoms

     Symptoms include fever, muscle pain, sore throat, vomiting, diarrhea, and internal and external bleeding, leading quickly to death. Although the disease has a high mortality rate, early detection increases a person's chance of survival. Due to the aid, and research done in those areas, the people can finally have some relief from this deadly virus. The previous treatment only treats symptoms, such as water and electrolytes to compensate for the loss due to the ebola-induced diarrhea. Patients who are severely ill however, require intensive treatment, and recovery is slow.













References

Chronology of Ebola Hemorrhagic Fever Outbreaks Known Cases and Outbreaks of Ebola Hemorrhagic Fever, in Chronological Order, CDC, updated 4 August 2014, accessed 31 July 2015

About Ebola Hemorrhagic Fever, CDC, updated 1 August 2014, accessed 31 July 2015.

Email Facebook LinkedIn Pinterest Print Tumblr Twitter