British drugmaker AstraZeneca said on Monday that one of the world’s leading Covid-19 vaccine candidates which is being developed by the University of Oxford, produces a immune response in both young and old adults. The development raises hopes of a path out of the gloom and economic destruction brought by the novel coronavirus. AstraZeneca said the Oxford vaccine candidate also triggers lower adverse responses among the elderly. A vaccine that works is seen as a game-changer in the battle against the novel coronavirus, which has killed more than 1.15 million people, shuttered swathes of the global economy and turned normal life upside down for billions of people.