A WHO advisor and Australian professor of epidemiology fears the Delta outbreak in Sydney will go on and on - or worse, that state leaders will just give up trying to fight it. A lockdown in greater Sydney is due to expire at the end of August, but daily case numbers aren't coming down - 233 new infections yesterday, about 50 of which were infectious in the community. Even the premier Gladys Berejiklian, not for the first time, is warning the sitation will deteriorate further. Worldwatch's Max Towle spoke to Mary-Louise McLaws of the University of New South Wales - she wants to see more rapid testing targeting certain workplaces.