Geneva, Nov 28 : Countries with decreasing Covid-19 numbers still need to stay "vigilant", a top World Health Organization (WHO) official said. "Even as case numbers are coming down, all countries need to remain vigilant. You've heard of this before, but we really need to emphasize it again. Do not let your guard down," Xinhua news agency quoted Maria Van Kerkhove, technical lead for WHO's Health Emergencies Program, as saying at a virtual briefing on Friday. "It's good to see the measures taking effect and transmission going down. But it's not time to let up. It's time to even scale up. "What we don't want to see is situations where you are moving from a so-called lockdown state to bring the virus under control to moving to a so-called lockdown state," Van Kerkhove added. The overall number of global coronavirus cases has topped 61.5 million, while the deaths have surged to more than 1.44 million, according to the Johns Hopkins University. In its latest update on Saturday, the University's Center for Systems Science and Engineering (CSSE) revealed that the current global caseload and death toll stood at 61,585,651 and 1,441,875, respectively. The US is the worst-hit country with the world's highest number of cases and deaths at 13,086,367 and 264,842, respectively, according to the CSSE. India comes in second place in terms of cases at 9,309,787, while the country's death toll soared to 135,715. /IANS