New Zealand's rate of border failures is three times higher than Australia. In just-released reports, airborne transmission is being considered the most likely cause for the spread of Covid-19 at two managed isolation facilities in March and April. Joint Head of Managed Isolation and Quarantine Brigadier Jim Bliss says all of the recommendations in the reports have either been completed or are underway. Max Towle speaks to Otago University epidemiologist Professor Michael Baker.