Holidays in Japan, China and South Korea made for thin conditions, and politics added extra uncertainty with elections in Canada and Germany bookending the week
The broad gains put the region on course to end a strong week on a positive note as concerns about the fast-spreading Delta variant, which weighed on confidence for much of August, gave way to optimism over the recovery outlook
Investors are also awaiting Federal Reserve chair Jerome Powell's speech at the Jackson Hole symposium for clues over any tapering of stimulus measures
MSCI's broadest index of Asia-Pacific shares outside Japan was last off slightly, but still up 3.7% so far this week. The index fell to its lowest in 2021 at the end of the previous week
The FDA move "is paving the way for organisations to mandate vaccines for workers and thus lift vaccination rates higher", said National Australia Bank's Tapas Strickland
The benchmark Nikkei 225 index was up 0.70 percent or 191.98 points at 27,686.22 in early trade, while the broader Topix index edged up 0.75 percent or 14.28 points to 1,929.42
Investors have for more than a year sent valuations surging on the back of colossal government and central bank support as well as optimism that the rollout of vaccines will help fight back against the coronavirus and allow economies to reopen
The rouble-based MOEX index hit an all-time high of 3,949.07 points on Aug. 18, before fading as prices for oil, Russia's main export, tumbled. But passing the 4,000 threshold seems only a matter of time