SYDNEY : Australia is not worried about AstraZeneca Plc's decision to put on hold its COVID-19 vaccine trial, its deputy chief medical officer said on Wednesday, as daily cases nudged higher in the country's coronavirus hot spot.AstraZeneca on Tuesday said it has paused a late-stage trial of one of the leading COVID-19 vaccine candidates after an unexplained illness in a study participant.The nature of the case and when it happened were not detailed, although the participant is expected to recover, according to Stat News, which first reported the news."With the information that I have got at the moment, I am not worried about it," Australia's Deputy Chief Medical Officer Nick Coatsworth told Sky News, adding the hold on trials does not mean.