• The Bank of Japan's quarterly tankan survey showed on Monday business sentiment in Japan improving in the three months to December.
• In coronavirus developments stateside, CDC Director Robert Redfield has signed off on Pfizer's Covid-19 vaccine, allowing inoculations to officially move forward for people ages 16 or older.

SINGAPORE — Stocks in Asia-Pacific were mixed in Monday trade, as investors in the region react to the approval of Pfizer's Covid-19 vaccine.

Mainland Chinese stocks were higher on the day: The Shanghai composite gained 0.66% to 3,369.12 while the Shenzhen component advanced 1.011% to 13,692.13. The Hang Seng index in Hong Kong dipped about 0.44% to close at 26,389.52.

In Japan, the Nikkei 225 gained 0.3% to close at 26,732.44 while the Topix index rose 0.48% to end its trading day at 1,790.52.

The Bank of Japan's quarterly tankan survey showed on Monday business sentiment in Japan improving in the three months to December. The headline index for big manufacturers' sentiment improved to minus 10 as compared with minus 27 in September. A median market forecast had expected the figure to come in at minus 15, according to Reuters.

In Southeast Asia, Singapore's Straits Times Index led gains among the region's major markets as it rose 1.29% to close at 2,858.14.

Singapore's Prime Minister Lee Hsien Loong announced Monday that the country's Health Sciences Authority had approved Pfizer-BioNTech's Covid-19 vaccine, with the first shipment set to arrive by the end of this month. Other vaccines are also expected to arrive in the country "in the coming months," he said.

"If all goes according to plan, we'll have enough vaccines for everyone in Singapore by the third quarter of 2021," Lee said.

The number of Covid-19 cases in the city-state has remained low for the past several weeks, with zero or one new case reported in its daily statistics.

Over in South Korea, the Kospi shed 0.28% to close at 2,762.20. South Korea has been dealing with a recent resurgence in coronavirus infections, with the country reporting its largest daily caseload ever on Sunday, according to local news agency Yonhap.

Shares in Australia edged higher on the day, with the S&P/ASX 200 up 0.26% to 6,660.20.

MSCI's broadest index of Asia-Pacific shares outside Japan was fractionally lower.

In coronavirus developments stateside, CDC Director Robert Redfield has signed off on Pfizer's Covid-19 vaccine, allowing inoculations to officially move forward for people ages 16 or older. That came following the FDA emergency authorization of Pfizer's vaccine. The U.S. has begun to ship the doses to hundreds of distribution centers across the country.

Alibaba, Tencent shares drop

Hong Kong-listed shares of Alibaba and Tencent dropped on Monday, declining 2.63% and 2.89%, respectively.

Alibaba Group and Tencent Holdings-backed China Literature were among firms set to be fined 500,000 yuan each ($76,467) by China's market regulator for failing to report deals properly for anti-trust reviews, according to a Monday announcement. China Literature's stocks in Hong Kong fell 4.12% on Monday.

Currencies and oil

The U.S. dollar index, which tracks the greenback against a basket of its peers, was at 90.639 after recently seeing levels above 91.

The Japanese yen traded at 103.81 per dollar following a strengthening last week form levels above 104.4 against the greenback. The Australian dollar changed hands at $0.756, having risen from levels below $0.749 last week.

Oil prices were higher in the afternoon of Asia trading hours, with international benchmark Brent crude futures up 0.8% to $50.37 per barrel. U.S. crude futures also rose 0.75% to $46.92 per barrel.

— CNBC's Emma Newburger contributed to this report.