* Wall Street indexes down in early trading * Sterling slips * Rising COVID-19 cases in focus (Updates with early U.S. market action, changes dateline, previous LONDON) NEW YORK, Dec 8 (Reuters) - Global equity indexes were mostly lower on Tuesday as investors struggled to keep the rally of recent weeks going with COVID-19 infections still surging, while Brexit deal talks weighed on sterling. The S&P 500 and Nasdaq were down slightly in early New York trading, with new cases threatening to further dampen the economy and investors awaiting progress in ongoing negotiations for a fresh COVID-19 relief package. Nationwide in the United States, COVID-19 infections are at their peak, with an average of 193,863 new cases reported each day over the past week, according to a Reuters tally of official data. “The rise in cases across the U.S. seems finally to have galvanized American lawmakers into action, although the $900 billion discussed is certainly well below the mooted levels of late summer, and even this amount may not make it through unscathed,” said Chris Beauchamp, chief market analyst at IG. Investors were trying to assess how widely and quickly vaccines might be available. A 90-year-old grandmother became the world’s first person to receive a fully-tested COVID-19 shot as Britain began mass-vaccinating its people in a global drive. The Dow Jones Industrial Average rose 17.89 points, or 0.06%, to 30,087.68, the S&P 500 lost 4.51 points, or 0.12%, to 3,687.45 and the Nasdaq Composite dropped 29.13 points, or 0.23%, to 12,490.82. Also, Tesla announced a $5 billion capital raise on Tuesday, its second such move in three months, as the electric-car maker cashes in on a rally in its shares this year. The pan-European STOXX 600 index rose 0.09% and MSCI’s gauge of stocks across the globe shed 0.10%.In the foreign exchange market, sterling was last trading at $1.331, down 0.49% on the day, while the dollar index was up slightly. British Prime Minister Boris Johnson said on Tuesday that Britain could abandon post-Brexit trade talks, a day after he agreed to meet the head of the European Commission in a last-ditch attempt to break the stalemate. Investors are also awaiting a two-day EU summit that begins Thursday, and the bloc is ready to set up its planned EU stimulus without Hungary and Poland, which are maintaining their veto of the EU budget. Most U.S. Treasury yields were lower as investors watched for news on vaccines and their distribution. The benchmark 10-year yield was down 2.7 basis points in morning trading at 0.9014%, close to the 0.9% threshold it was last below on Dec. 1. Oil prices were also lower, while spot gold prices were higher.