* Mining index rises on Fortescue, BHP, and Rio boost

* Trading volumes low ahead of holiday on Tuesday

* NZ index closes 0.5% firmer, Oceania Healthcare top gainer

Jan 25 (Reuters) - Australian shares closed higher on Monday after the country's drug regulator approved the Pfizer-BioNTech COVID-19 vaccine for use, while expectations of a $1.9 trillion fiscal stimulus plan to kick-start the U.S economy lifted broader sentiment.

Global equity markets have scaled record highs in recent days on bets COVID-19 vaccines will start to reduce the infection rates worldwide and on a stronger U.S. economic recovery under President Joe Biden.

The S&P/ASX 200 index closed 0.4% firmer at its highest since Feb. 25, 2020, after ending 0.3% lower on Friday. Trading volumes remained at just little over half of the 30-day average.

The country's medical regulator was one of the first in the world to complete a comprehensive approval of the Pfizer-BioNTech vaccine, while Australian Health Minister Greg Hunt told reporters that vaccination of priority groups is expected to begin by February-end, at 80,000 doses per week.

"Volumes are low, and there isn't a lot of activity simply because it's Australia day on Tuesday," said Brad Smoling, Managing Director of Smoling Stockbroking.

"The market is taking some relief due to the low number of coronavirus cases and the highly acclaimed Pfizer vaccine that will be rolled out in Australia," he said.

Markets will be closed on Tuesday on account of Australia Day.

Miners rose nearly 1.1%, and were the biggest boosts to the index with mining giant Rio Tinto gaining 2.1%, while rival BHP rose nearly 0.89%.

Technology stocks advanced 1.1%, with buy-now-pay-later heavyweight Afterpay rising 1.4%. Aerial imagery services provider Nearmap jumped 5.1% and data services company Appen closed 2.8% firmer.

Energy stocks were the biggest drags on the benchmark, down 1.2% to their lowest in nearly two weeks, as prices inched lower on concerns of tepid demand following a rise in U.S. crude inventories and fresh restrictions in China.

Woodside Petroleum and Santos both shed more than 1%.

New Zealand's benchmark S&P/NZX 50 index rose 0.5% to finish the session at 13,399.1 points.

Residential aged-care services provider Oceania Healthcare and business mail services provider Freightways were the top gainers in the benchmark. (Reporting by Harish Sridharan in Bengaluru, Editing by Sherry Jacob-Phillips)