US stock index futures pulled back on Wednesday after the S&P 500 and the Nasdaq closed at record levels, with investors awaiting monthly private job creation that will provide new hints on the economy’s well-being.Hopeful updates on coronavirus vaccine have helped investors look past the record-breaking jump in infections and increase bets on a speedy recovery the upcoming year, powering the Wall Street’s major indexes to life-highs recently.Pfizer Inc and BioNTech’s coronavirus vaccine got the green light for use in Britain, the first Western country to approve a shot for coronavirus.Meanwhile, US officials on Monday revealed details of their plan to distribute vaccines to millions of Americans starting later this month.