By Alun John

HONG KONG, Dec 23 (Reuters) - A global share rally continued in early Asian trading on Thursday and the safe haven dollar was on the back foot as markets took cheer from positive signs about the impact of the omicron variant of COVID-19 and U.S. economic data.

Japan's Nikkei gained 0.3% and MSCI's broadest index of Asia-Pacific shares outside Japan rose 0.6%, a third successive session of gains after taking a jolt on Monday when fears about the new strain of coronavirus gripped markets and pushed investors to safe haven assets.

"The unpredictable path of the pandemic and its related impacts on growth and inflation continue to dominate investor risk appetite," said David Chao global market strategist Asia Pacific at Invesco.

"The recent health data from the UK and other places around the world indicate that the worst case is unlikely: even though transmission rates are reportedly higher, this variant seems less virulent and less prone to cause serious illnesses or death."

The risk of needing to stay in hospital for patients with the Omicron variant of COVID-19 is 40% to 45% lower than for patients with the Delta variant, according to research by London's Imperial College published on Wednesday.

Overnight the Dow Jones Industrial Average rose 0.74%, the S&P 500 gained 1.02%, and the Nasdaq Composite added 1.18%, after data showed U.S. consumer confidence improved further in December, and the White House said it was resuming talks on a massive social spending and climate change bill with holdout senator Joe Manchin.

However, while markets on both sides of the Pacific have gained this week, MSCI's broad Asian benchmark's gains began from Monday's year low, while U.S. benchmarks are in sight of last month's record highs.

Strong economic growth in the United States and jitters sparked by sweeping regulatory changes in China earlier this year which roiled shares in industries from technology, to property have driven investment away from Asia.

Hong Kong's Hang Seng Index has been hard hit, falling 15% in 2021, which would be its worst year since 2011.

On Thursday, the benchmark rose 0.45%, though index constituent JD.com's shares dropped as much as 9% after the ecommerce company's largest shareholder Tencent said it would give most of its $16.4 billion stake to its own shareholders as a dividend.

In currency markets, in line with the "risk on" mood the dollar index was at 96.042, not far from the overnight low of 96.020, touched for the first time since Dec. 17.