The World Health Organization warned on Monday that there might never be a "silver bullet" for Covid-19 in the form of a perfect vaccine and that the road to normality would be long, with some countries requiring a reset of strategy.

More than 18.14 million people around the world are reported to have been infected with the disease and 688,080 have died, according to a Reuters tally, with some nations that thought they were over the worst experiencing a resurgence...