BERLIN : German Chancellor Angela Merkel warned on Friday that the coronavirus pandemic would worsen in coming months, and that life would not return to normal until a vaccine against it had been developed.Western Europe's longest serving leader also called on the world to accelerate the fight against global warming, and for Germany and Europe to maintain dialogue with other major powers through difficult times while beating the drum for democracy.But as Merkel makes preparations to step down before the next national election in October 2021, she made clear that she expects the pandemic to define her last year in office.Urging citizens not to drop their guard against the virus as Germany's daily infection rate rises, she told a news.