A leading epidemiologist has raised concerns about a proposal to use rapid antigen testing to boost crowd numbers for the AFL grand final in Melbourne.
Ex-Collingwood president Eddie McGuire has floated allowing up to 100,000 fans into the MCG for the AFL decider in late September, after it was moved to Brisbane last year amid the state's second wave of COVID-19.
He wants a "ring of steel" around Melbourne's sports precinct and 200 sites to carry out rapid antigen testing for all fans and officials.
But Dr Catherine Bennett, inaugural chair of epidemiology at Deakin University, said rapid antigen tests were far from foolproof and could result in positive cases slipping through.
"If instances are actually quite low in the community, these tests are not quite so reliable. They can miss cases," she told AAP on Thursday.
"What we do know is that people with this particular virus have a very high viral load initially. That probably means these tests are better at screening them out."
She argues recent cases of transmission linked to the MCG and AAMI Park have changed the way authorities assess large outdoor crowds, forcing them to look at new ways to mitigate the increased risk posed by the highly infectious Delta strain.
"It could be that spectators have screening and or vaccination, and or immunity. All these things will be things they look at ... to try and bring these events forward," Dr Bennett said.
"If we don't do those things, we don't recognise that people will have different risk levels, then we just have to keep pushing events back."
But while introducing more safeguards will help get crowds back, Dr Bennett said vaccination rates remain the key to restoring order.
"That will also help us contain local outbreaks and make it less likely they will take off," she said.
"All of those things by November are probably starting to look better for the Melbourne Cup. But a September AFL final - it's only a couple of months away."
This week, Victoria Racing Club chief executive Steve Rosich wrote to members with a plan to allow 60,000 spectators at November's Melbourne Cup.
Premier Daniel Andrews said crowd plans for upcoming events would be assessed by health authorities on a case-by-case basis.
"I can't tell you how many people will be at the grand final, but I'm determined to have people at the grand final and as many as we can safely get in," he told reporters.
"The same for the racing carnival, the same for Harry Potter, the same for Moulin Rouge."
He similarly dismissed the efficacy of rapid testing, saying they were less reliable than the widely used polymerase chain reaction (PCR) test.
"The notion of one rapid test being the same as that kind of diamond standard PCR test ... I'm not going to have that argument with anyone because they aren't as accurate," Mr Andrews said.
But opposition health spokeswoman Georgie Crozier said they should still play a part in the state's testing toolkit for aged care facilities, hospitals, small businesses and events.
"It's not perfect but we know there are false positives with PCR testing too," she said.
Australian Associated Press