Shares of companies testing Ebola vaccines rise

Ebola stocks to watch
Ebola stocks to watch   

Shares of some companies that are studying potential vaccines for Ebola climbed after federal officials announced that the first case of the disease has been diagnosed in the U.S.

The Centers for Disease Control said a patient being treated at a hospital in Dallas tested positive for the disease.

Read MoreWhat we know about the Texas Ebola patient

Ebola is believed to have sickened more than 6,500 people in West Africa, and more than 3,000 people have died.

Hemera | 360 | Getty Images

The World Health Organization has worked to speed up the use of some experimental vaccines and companies are ramping up testing. Earlier this month NewLink Genetics said it would start safety testing of a vaccine within a few weeks, while Inovio Pharmaceuticals said it would start human trials of a DNA-based vaccine in early 2015.

Read MoreThere won't be an Ebola outbreak in US: Virologist

Shares of Inovio Pharmaceuticals shares rose 35 cents, or 3.6 percent, to $10.20 in aftermarket trading, while NewLink Genetics shares gained $2.68, or 12.5 percent, to $24.10. Stock of some other companies that have been involved in efforts to come up with vaccines and medications also jumped. BioCryst Pharmaceuticals added $1.26, or 13 percent, to $11.04; Sarepta Therapeutics rose $1.57, or 7.4 percent, to $22.67; and Tekmira Pharmaceuticals stock climbed $5.97, or 28 percent, to $27.11.

Read More100 doses of Ebola drug available: Sarepta CEO

Ebola diagnosed in Texas patient
Ebola diagnosed in Texas patient   

Ebola's symptoms can start as much as 21 days after exposure, and the disease isn't contagious until symptoms begin. It takes close contact with bodily fluids to spread.

Read MoreEbola: A closer look at the 'frightening disease'