SYDNEY, Nov 26 (Reuters) - Australia on Friday said it was investigating the newly identified COVID-19 variant spreading in South Africa and warned it may close its borders to travellers from the African nation if risks from the new strain rise. South African scientists are concerned the new variant could evade the body"s immune response and make it more transmissible as it has a "very unusual constellation" of mutations. Australia Health Minister Greg Hunt said he would swiftly respond if the World Health Organization (WHO) classifies it as a major new variant. "As we have always been, we are flexible. And if the medical advice is that we need to change that, we won"t hesitate," Hunt told reporters in Sydney. "That is what we have done as a country, whether it has been closing borders, whether it has been ensuring there is quarantine." Alarmed by the variant, Britain temporarily banned flights from South Africa, Namibia, Botswana, Zimbabwe, Lesotho and Eswatini from Friday, and asked returning British travellers from those destinations to quarantine. read more UK health officials said the new strain could make vaccines less effective as it has a spike protein that was different from the one in the original coronavirus that vaccines are based on. The WHO said it would take "a few weeks" to understand the impact of the new variant. Australia early this month eased its international border restrictions for the first time during the pandemic allowing fully vaccinated residents to return to the country without quarantine after higher vaccination levels. Australia had largely stamped out infections for most of this year until an outbreak of the highly infectious Delta variant in late June spread rapidly across its east. About 205,000 cases and 1,985 deaths have been recorded so far, lower than many other countries in the developed world.