US stock index futures increased on Monday as hopes that the first coronavirus vaccine could be available within weeks renewed bets of a swift economic comeback next year.The US Food and Drug Administration is likely to approve in mid-December the development of the vaccine made by Pfizer Inc and German partner BioNTech, a top official of the government’s vaccine distribution effort stated on Sunday.Global equity markets received a leap earlier on Monday as AstraZeneca Plc became the latest main drugmaker to say its coronavirus vaccine might be roughly 90% effective, although its shares dropped 1.8% as some traders perceived the efficacy data as discouraging compared with rivals.At 7:07 a.m. ET, Dow e-minis increased by 142 points, or 0.49%, S&P 500 e-minis increased by 15.25 points, or 0.43%, and Nasdaq 100 e-minis increased by 30 points, or 2.25%.