A modified version of AstraZeneca's COVID-19 vaccine tailored to combat a coronavirus variant first documented in South Africa could be ready by the end of 2021, an AstraZeneca official in Austria said in an interview published on Sunday. Sarah Walters, AstraZeneca's Austria country manager, told the Kurier newspaper that studies, so far, indicating the existing AstraZeneca vaccine was less effective against the more infectious variant first documented in South Africa were "too small to draw final conclusions". "In the meantime, AstraZeneca and Oxford University have started on modifications to the vaccine for the South African variant and we expect it will be ready by the end of the year, should it be needed," Walters told the Kurier. Walters blamed challenges – including delivery delays for the AstraZeneca shot in the European Union – on the "complex process" of producing a vaccine, coupled with the extremely high demand arising from the coronavirus pandemic.