Nov 29 (Reuters) - Wall Street stocks closed higher on Monday, regaining some of the ground lost in Friday"s sell-off, as investors appeared hopeful that the Omicron coronavirus variant would not lead to lockdowns after reassurance from U.S. President Joe Biden. Nasdaq led gains among the major averages with help from the technology sector, while the S&P and the Dow advanced after suffering their biggest one-day percentage declines in months in Friday"s holiday-shortened session as investors worried that the latest COVID-19 variant would cause economic disruption. read moreBiden said on Monday that Omicron-related lockdowns were off the table for now, though he noted the variant was a cause for concern but not for panic. He urged Americans to get vaccinated and wear masks indoors. He also said the United States was working with pharmaceutical companies to make contingency plans if new vaccines were needed. read more Those comments and indications from drug companies that they are taking the variant seriously were reassuring for investors, who had been anxious about the potential for further COVID restrictions.Friday was a major de-risking event. You had the market go back to its worst fears of COVID spreading and the return of lockdowns." said Edward Moya, senior market analyst at OANDA. "Now you"re starting to see there is some optimism when you listen to the President, when you listen to the Pfizer CEO. The Omicron panic is easing, and we"re into a period of wait and see." Vaccine makers such as Pfizer (PFE.N), its partner BioNTech (22UAy.DE) and their rivals Moderna (MRNA.O) and Johnson & Johnson (JNJ.N) said Monday they are working on vaccines that specifically target Omicron in case their existing shots are not effective against the variant. read more nFWN2SK0VH] "It"s not like the start of the pandemic all over again," said Carol Schleif, deputy chief investment officer for the BMO family office in Minneapolis who also noted that after Friday"s knee-jerk reaction, investors have been trained this year to buy the dip. "People are willing to just take a deep breath and try to reassess, be a little more patient." According to preliminary data, the S&P 500 (.SPX) gained 58.74 points, or 1.28%, to end at 4,654.43 points, while the Nasdaq Composite (.IXIC) gained 288.61 points, or 1.86%, to 15,780.27. The Dow Jones Industrial Average (.DJI) rose 226.75 points, or 0.65%, to 35,126.09. Among the S&P"s 11 major sectors, technology (.SPLRCT) led the percentage gains. Amazon.com (AMZN.O) and Tesla Inc (TSLA.O) rose, helping to boost the consumer discretionary sector (.SPLRCD) with investors viewing Friday"s losses as a cue for bargain-hunting on high-value tech names. While the Dow (.DJI) advanced, it underperformed its peers with pressure from Merck & Co Inc (MRK.N), which extended losses from Friday. Updated data from a study of its experimental COVID-19 pill showed lower efficacy in reducing risk of hospitalization and deaths than previously reported. read more Twitter Inc (TWTR.N) lost ground after the social media firm said CEO Jack Dorsey will step down and be succeeded by Chief Technology Officer Parag Agrawal. Dorsey had been in the unusual position of having the CEO job of two major technology companies, the second being digital payments firm Square Inc (SQ.N). read more Advanced Micro Devices (AMD.O) rose after a report that electric-car maker Tesla has started using a new AMD chip in Model Y vehicles in China. Tesla"s shares gained after a report that chief Elon Musk urged employees to reduce the cost of vehicle deliveries. Other big boosts from single stocks in the S&P came from Microsoft (MSFT.O) and from Apple Inc (AAPL.O), which gained ground after HSBC raised its price target on the iPhone maker"s stock.