ALEXANDER WINNING SOUTH African scientists are testing whether vaccines will be less effective against a COVID-19 variant first detected locally and hope for initial results within two weeks, a professor at the national communicable disease institute said. The variant, known as 501Y.V2, was identified by South African genomics experts late last year and is thought to be more contagious than older variants. Professor Penny Moore told Reuters the National Institute of Communicable Diseases had received samples from several local vaccine trials, including Oxford University and AstraZeneca's shot, and would try to find out whether antibody responses are reduced against 501Y.V2.…