coronavirus vaccine trial fuelled optimism around the world Tuesday that humanity may be a step closer to defeating the worst pandemic in a century.Some of the industries hit hardest by travel curbs, social distancing and lockdowns rebounded on hopes that the world may return to normal, after pharma giant Pfizer and its German partner BioNTech announced Monday that their vaccine candidate was 90% effective in preventing Covid-19.A vaccine is seen as the best hope to break the cycle of deadly virus surges and severe restrictions across much of the world since Covid-19 first emerged in China late last year and unleashed devastation on the global economy."Bombed-out sectors such as aviation, travel, leisure, big oil...