Wall Street stocks rebounded early Friday buoyed by positive news about coronavirus vaccines and after a top Biden administration official reiterated support for a massive economic relief package. After Thursday's retreat, equities were back on the upswing as Pfizer and BioNTech said research showed their Covid-19 vaccine could be stored at standard freezer temperatures, potentially lowering the costs and logistical challenges of widespread inoculation against the deadly virus. Analysts also pointed to comments late Thursday by Treasury Secretary Janet Yellen once again making the case for President Joe Biden's $1.9 trillion pandemic aid package. About 25 minutes into trading, the Dow Jones Industrial Average was up 0.2 percent to 31,553.15. The broad-based S&P 500 gained 0.3 percent to 3,924.89, while the tech-rich Nasdaq Composite Index advanced 0.5 percent to 13,934.62. The S&P 500 is down modestly for the week amid worries that higher US Treasury yields presage a jump in inflation. Analysts have also pointed to concerns over excessive equity valuations following a series of Wall Street records. But Yellen downplayed inflation concerns, and she was backed by IMF chief economist Gita Gopinath who on Friday dismissed fears about rising prices saying they are "nothing to be concerned about." Among individual companies, Deere & Co. jumped almost 10 percent after reporting that quarterly profits more than doubled to $1.2 billion amid improvement in the agricultural and construction sectors. NXP Semiconductors rose 2.5 percent, recovering some losses from earlier in the week after announcing that the Texas power crisis forced it to idle two plants in Austin. jmb/hs