U.S. stock index futures were marginally higher on Friday morning amid low trading activity due to the Thanksgiving holiday.At around 3 a.m. ET, the Dow Jones pointed to a rise of around 12 points. Futures on the S&P 500 and Nasdaq also suggested a slightly higher open. Equity markets are due to close at 1 p.m. E.T. on Friday.More broadly, global stocks have pulled back from their rally earlier this week. The Dow Jones Industrial Average fell on Wednesday, taking a breath after breaking above 30,000 points Tuesday.The rally came after the Donald Trump administration began the transition process for President-elect Joe Biden, and news surrounding the incoming president’s appointments .In Europe, shares of AstraZeneca slipped another 0.9% on Friday with questions over the way AstraZeneca and Oxford University tested their coronavirus vaccine. The head of the White House’s vaccine task force voiced doubts earlier in the week about trial data and the drug’s efficacy rate.