NEW YORK: The dollar was steady on Tuesday and the yen stayed low, as investors remained optimistic about progress towards a Covid-19 vaccine and the currency markets digested the big moves of Monday.

US drugmaker Pfizer Inc and German partner BioNTech SE said on Monday a large-scale clinical trial showed their vaccine was more than 90% effective in preventing Covid-19 - news which lifted global markets with a wave of risk appetite.

The dollar's rise on Monday of 0.5%, analysts said, was caused by investors quitting long positions in other major safe-haven currencies such as the Japanese yen and the Swiss franc.

The dollar had lost around 1.4% this month until Democrat Joe Biden's victory in the US presidential election became apparent over the weekend.

The Japanese yen, which had its biggest one-day fall since March after the vaccine announcement, was little changed Tuesday morning in New York at 105.34 yen to the dollar. The yen had initially clawed back some of its from the day before.

The Swiss franc gained marginally, with the dollar rising 0.1% to 0.915 francs after Monday's 1.5% gain.

Euro-dollar was broadly flat at $1.1813.

The Australian dollar - seen as a liquid proxy for risk appetite - was off nearly 0.3% versus the dollar, giving back its jump in the immediate aftermath of the vaccine news.

The New Zealand dollar was off 0.1% and poised to end its streak of seven consecutive session of gains.

China's offshore yuan, which has been gradually strengthening since May, was flat on Tuesday after hitting 2.5-year highs versus the US dollar on Monday.-Reuters