Feb 16 (Reuters) - Canada’s main stock index opened higher on Tuesday as hopes of fresh U.S. stimulus and faster COVID-19 vaccine rollouts helped strengthen economic recovery optimism, while higher oil prices aided sentiment. * At 9:31 a.m. ET (1431 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was up 97.78 points, or 0.53%, at 18,557.99. (Reporting by Shashank Nayar in Bengaluru; Editing by Aditya Soni)