Victoria's success in controlling it by social restrictions is probably also what prompted British Prime Minister Boris Johnson to impose his own recent hard lockdown in England, Professor Purcell said. The variant seen in Victoria, known as N501Y, has several key mutations also seen in the British and South African variants. Advertisement âSome of the viruses that came out of hotel quarantine in Victoria had some of these key mutations,â said Professor Purcell. Victoria's Health Department declined to comment. Boris Johnson. Credit:AP The British variant, known as B.1.1.7, emerged in September and appears to sport an unusually large number of changes to its genetic code. A second variant, 501.V2, emerged independently in South Africa at about the same time with similar mutations.