European shares struggled on Tuesday as worries over the coronavirus pandemic overshadowed Chinese trade data that pointed to a buoyant recovery, while the U.S. dollar edged away from a three-week low.

The Euro STOXX 600 .STOXX fell 0.4% before trimming losses, with markets in Frankfurt .GDAXI, London .FTSE and Paris .FCHI mirroring its moves. It was last down 0.2%, on course to end three straight days of gains.

Keeping markets on edge, traders said, was news that Johnson & Johnson JNJ.N was pausing its COVID-19 vaccine candidate clinical trials because of an unexplained illness in a study participant.

Investors see the quick introduction of a vaccine as key to helping economies recover. J&J's move comes after AstraZeneca AZN.L paused late-stage trials of its experimental vaccine in September, also due to a participant's unexplained illness.

The travel and leisure .SXTP and autos .SXAP sectors suffered, losing 1% and 0.3% respectively after heavier falls in early trading.

Wall Street was also set to lose ground. S&P 500 futures ESc1 recovered most of their earlier losses to trade down 0.1%.

The risk-off mood contrasted with earlier resilience for Asian markets. They recovered losses after Chinese data showed exports rising 9.9% in September and imports swinging to a 13.2% gain versus a 2.1% drop in August.

The data, which suggests Chinese exporters are recovering from the pandemic's damage to overseas orders, helped MSCI's broadest index of Asia-Pacific shares outside Japan .MIAPJ0000PUS gain 0.2%.

Chinese blue-chip shares .CSI300 added 0.3% after dipping early in the day. Some investors, though, raised questions about how strong consumer demand would prove to be.

“The question is not necessarily how China’s trade is doing per se, but how well will consumers spend on Christmas to give some sense of normalcy amid a period of great stress,” said Nordea Investments’ Sebastien Galy in a note.

Currency traders were also watching Chinese trade-related issues. Reports that Beijing has stopped taking shipments of Australian coal caused the Australian dollar to drop as much as 0.6% to $0.7165 AUD=D4.

The MSCI world equity index .MIWD00000PUS, which tracks shares in nearly 50 countries, fell 0.1%.

Government bond yields in the euro zone held near recent troughs, with hefty supply failing to dent a market bolstered by expectations for further central bank easing.

Germany's 10-year Bund yield touched -0.538% DE10YT=RR, its lowest in just over a week. Italian IT10YT=RR and Greek GR10YT=RR benchmark 10-year debt both hit record lows.
STIMULUS HOPES

Investors increasingly expect Democratic candidate Joe Biden will win the U.S. presidential election next month. That would probably lead to a big stimulus package to help the coronavirus-battered U.S. economy.

“Biden effectively leading in the polls is removing some element of uncertainty,” said Jeremy Gatto, an investment manager at Unigestion in Geneva. “In investors’ minds, it’s not a question of if we get a stimulus, but when.”

Some expect a Biden win to undermine the U.S. dollar, since he's pledged to raise corporate tax rates. But the dollar rose 0.2% against a basket of other currencies to 93.214 =USD, trying to extend a rebound from Friday's near-three-week low of 92.997.

The Chinese yuan fell 0.1% to 6.7466 per dollar CNH=, after the central bank set a weaker-than-forecast midpoint, offsetting any boost from the trade data.