Source: Tekmira Pharmaceuticals

Medical experts believe it was just a matter of time before Ebola made its way across the Atlantic to America. The first case in the U.S. was confirmed last week, and it's possible that there will be more cases in the future.

But while that prospect may seem frightening, Ebola isn't spread easily and a slate of emerging biotech companies, like Tekmira Pharmaceuticals Corporation (NASDAQ:ABUS) and Sarepta Therapeutics Inc. (NASDAQ:SRPT), as well as large drugmakers, including GlaxoSmithKline (NYSE:GSK), are hard at work developing new therapies that target the tough to treat disease.

First, a bit of background on Ebola
Ebola is a severe and often fatal disease, but it's rare and nearly all the cases of the most recent outbreak in West Africa have been from human to human transmission through contact with either the infected person's bodily fluids or with items, such as bedding, that have been contaminated with those fluids. The incubation period is between two and 21 days and patients aren't infectious until symptoms develop; however, patients can remain contagious for as many as seven weeks following recovery.

The disease was first identified in 1976 and prior to this latest outbreak in Africa, outbreaks have been relatively small and contained. The current outbreak, however, is the biggest one on record and accounts for more deaths than all previous Ebola outbreaks combined. The World Health Organization estimates that 6,500 people have contracted Ebola and more than 3,000 people have died since March in several West African countries, including Guinea, Liberia, and Nigeria.

Currently, there aren't any drugs with regulatory approval for treating Ebola, so most of the assistance provided to patients includes palliative care such as rehydration and treating the symptoms of the disease.

Novel approaches
Although there are no approved vaccines for Ebola, a number of researchers -- both big and small -- are working on it.

For example, Tekmira has gotten a tremendous amount of media attention following the use of its experimental Ebola vaccine to treat a doctor that contracted the disease in Africa and returned to the United States for treatment last month.

Tekmira's aptly named TKM-Ebola sidestepped the typical FDA regulatory process, which requires extensive clinical studies and a formal review, after the FDA granted permission for emergency use on Dr. Sacra and others who had contracted the disease and were struggling to overcome it.

TKM-Ebola was developed by Tekmira thanks in part to $140 million in grants from the Department of Defense, but Tekmira isn't the only biotech company that has received money from the DoD to develop a vaccine. 

Sarepta Therapeutics, which also has a potential treatment for a rare muscular disease known as Duchenne muscular dystrophy, received $291 million from the DoD in 2010 to develop AVI-7537 for the possible treatment of Ebola. The program to develop AVI-7537, however, was shuttered in 2012 once funding ran out.

Sarepta hopes to rekindle that funding from the government and believes that if it does get funding it could create enough vaccine to treat 100 patients fairly quickly. So far, there's been no word if that funding is coming, but Sarepta remains hopeful given that AVI-7537 had a 60%-80% success rate in preclinical trials in monkeys.

Tekmira and Sarepta are intriguing; however, they remain development stage companies that don't yet have a dime of sales or any proven therapies on the market. That's not the case for GlaxoSmithKline, one of the globe's biggest drugmakers.

Source: GlaxoSmithKline

GlaxoSmithKline is working with the National Institutes of Health on another early stage Ebola vaccine that has shown promise in pre-clinical trials. Thanks to funding from the Wellcome Trust, Medical Research Council and the U.K. government, Glaxo is currently studying the vaccine in volunteers in the U.S. and U.K. in a small phase 1 trial and is creating up to 10,000 doses of the vaccine for emergency use, such as for healthcare workers.

Work to be done
Tekmira and Glaxo's respective vaccines are being tested in humans; researchers should have a better handle on efficacy over time. Sarepta could also come into play, but it's uncertain whether government funding will materialize, particularly given that a lot of resources are likely being funneled instead to the Tekmira and Glaxo programs. While Ebola is a serious condition, it does remain rare. Regardless, if Tekmira and Glaxo are successful, it's likely that both companies will see significant demand from countries looking to build up stockpiles so that the response to future outbreaks can be quicker. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.