Australia has secured a deal with the drug maker AstraZeneca to supply a potential Covid-19 vaccine to its entire population free of charge, the government announced Tuesday, becoming the latest country to lock in supplies of the drug should trials succeed. CNN reports that British-based AstraZeneca is developing the vaccine in partnership with Oxford University, with advanced trials now underway with thousands of volunteers across multiple countries. Under the deal, the Australian government would manufacture the vaccine and offer free doses to all citizens.