* AstraZeneca vaccine news drives risk-on approach

* Mexican peso hits strongest since March; EEM highest since 2018

* Gold hits four-month low (Updates prices)

By Rodrigo Campos

NEW YORK, Nov 23 (Reuters) - Stocks brushed against last week's record high on Monday before trading little changed and an index of commodity prices touched its highest since March as more vaccine-positive news gave investors hope economic activity could resume globally at a faster clip than has been thought.

AstraZeneca said its COVID-19 vaccine, cheaper to make, easier to distribute and faster to scale-up than its rivals, could be as much as 90% effective.

"This means we have a vaccine for the world," said Andrew Pollard, director of the Oxford University vaccine group that developed the drug.

Assets from emerging markets reacted strongly to the news, as it allays concerns over the distribution logistics of a vaccine for developing countries.

A popular emerging market stocks ETF was set to close at a 32-month high while the Mexican peso briefly strengthened to under 20 per dollar for the first time since March. The U.S. dollar index touched its lowest since Sept. 1 before edging higher, mostly at the expense of the euro.

Emerging market stocks rose 0.90% while MSCI's gauge of stocks across the globe gained 0.46%.

On Wall Street indexes were mixed with the Nasdaq underperforming as traders rotated away from big tech names.

Markets' optimism also came after a top official of the U.S. government's vaccine-development effort said Sunday that the first vaccines there could be given to U.S. healthcare workers and some others by mid-December.

"The market has moved higher with confidence that as we get better at treating and preventing this virus, economic activity will likely follow in the wake of that," said Art Hogan, chief market strategist at National Securities in New York.

The Dow Jones Industrial Average rose 354.88 points, or 1.21%, to 29,618.36, the S&P 500 gained 23.38 points, or 0.66%, to 3,580.92 and the Nasdaq Composite added 42.75 points, or 0.36%, to 11,897.72.

Oil prices added to last week's gains as traders anticipated the vaccine news would spur a recovery in energy demand.

"Investors are ignoring near-term headwinds, chief among which are surging global COVID infections, and instead looking ahead to next summer," said PVM analyst Stephen Brennock.

The United States surpassed 255,000 deaths and 12 million infections since the pandemic began, with daily infections at a record near 170,000 and daily deaths around 1,500.

U.S. crude rose 1.44% to $43.03 per barrel and Brent was at $45.98, up 2.27% on the day.

An index of commodity prices touched its highest since early March.

The dollar index rose 0.167%, with the euro down 0.08% to $1.1844.

The Japanese yen weakened 0.56% versus the greenback at 104.45 per dollar, while sterling was last trading at $1.3325, up 0.32% on the day.

The Mexican peso lost 0.04% versus the U.S. dollar at 20.16. Earlier it touched 19.9488 per dollar.

U.S. Treasury yields rose and the yield curve steepened as investors took encouragement from positive vaccine news.

Benchmark 10-year notes last fell 9/32 in price to yield 0.857%, from 0.829% late on Friday.

Gold fell to its lowest in four months as optimism over vaccine progress drove investors towards riskier assets.

Spot gold dropped 1.6% to $1,839.83 an ounce. Silver fell 2.17% to $23.62.

(Reporting by Rodrigo Campos; additional reporting by Sruthi Shankar, Sagarika Jaisinghani and Shivani Kumaresan in Bengaluru, Shadia Nasralla in London Editing by Nick Zieminski)