GENEVA—The World Trade Organization (WTO) became the first major diplomatic casualty of the new coronavirus variant on Friday when it postponed its first ministerial meeting in four years due to the deteriorating health situation. Ministers from WTO members were due to have gathered next week for a meeting widely seen as a test of the WTO’s relevance. The WTO said that its members had agreed late on Friday to postpone the ministerial conference after the new variant outbreak led to travel restrictions that would have prevented many ministers from reaching Geneva. No new date has been set for a rescheduled meeting. The World Health Organisation has classified the B.1.1.529 variant detected in South Africa as a “variant of concern,” saying it may spread more quickly than other forms of the virus. Scientists are also seeking to find out if it is vaccine-resistant. Switzerland, home to the WTO, on Friday banned …