Sentiment in U.S. stock futures overall was dampened early Wednesday after the U.S. confirmed its first case of Ebola. The unidentified patient arrived in the U.S. from Liberia on Sept. 20 and is now in "strict isolation" in Texas Health Presbyterian Hospital of Dallas.
But shares of Canada's Tekmira Pharmaceuticals soared in premarket trading on prospects for its Ebola drug. So did, Massachusetts-based Sarepta Therapeutics whose CEO Chris Garabedian told CNBC Tuesday that his company has enough doses of its Ebola treatment to handle about 100 patients.
Investors will also be watching the day's economic news—highlighted by preliminary ISM manufacturing data, which is seen showing a small decline in activity in September. There will also be construction spending for August.
The ADP private payrolls employment report is also out Wednesday with an eye to how the government's September non-farm payrolls will read on Friday.
Stocks to watch include Acuity Brands, which will post results before Wall Street opens.
Plus, JPMorgan Chase shares may wobble, after a federal judge warned on Tuesday that the bank could face a lawsuit from investors who claim they were misled about the safety of mortgage-backed securities sold before the financial crisis.
Outside of the U.S., Asian stocks were mixed as pro-democracy rallies in Hong Kong continued on Wednesday. Now in its fifth day, the mass campaign has spread to the city's Tsim Sha Tsui shopping district and is disrupting businesses.
Read MoreTraders lay their chips on Hong Kong protest plays
European markets also weakened, after Markit PMI data showed Germany's manufacturing sector contracted for the first time in 15 months in September.