World share markets dropped after the CEO of drugmaker Moderna warned that COVID-19 vaccines are unlikely to be as effective against the new variant.
Canada is a major producer of commodities, including oil, so the loonie tends to be sensitive to prospects for global growth.
U.S. crude oil futures fell nearly 4% to $67.23, while the Canadian dollar was trading 0.2% lower at 1.2767 to the greenback, or 78.33 U.S. cents.
The currency touched its weakest intraday level since Sept. 22 at 1.2812.
Canada's economy grew 5.4% in the third quarter on an annualized basis, beating analyst expectations for a gain of 3.0%, Statistics Canada data showed.
A preliminary estimate for October showed a gain of 0.8%, while September's GDP was in line with expectations for a 0.1% rise.
Canadian government bond yields were lower across a flatter curve, tracking the move in U.S. Treasuries.
The 10-year rate hit its lowest intraday level since Oct. 14 at 1.534% before recovering slightly to 1.546%, down 6.8 basis points on the day.
(Reporting by Fergal Smith; Editing by Nick Zieminski)