Study reveals mask rule turned Melbourne’s deadly second wave ‘overnight’

As Melbourne suffers its fifth Covid lockdown, it’s been revealed one measure turned the city’s deadly second wave in 2020 ‘almost overnight’.

World-leading research has revealed the mandating of masks during Melbourne’s deadly second wave turned the pandemic “almost overnight”.

The study from the Burnet Institute and published in the journal PLOS ONE found that masks were the single most important control measure and “turned the epidemic around”.

Co-lead author Nick Scott said the introduction of mandatory mask use by the Victorian government on July 22 last year while stage 3 restrictions were in place turned an exponential increase in community transmission into an exponential decrease “almost overnight”.

Mandating masks changed the course of Victoria’s deadly second wave overnight, research has revealed. Picture: NCA NewsWire / Ian Currie

“We had a unique situation in Melbourne where masks were made mandatory as a single policy change and compliance went from low use to very high use of masks in the community very rapidly,” Dr Scott said.

“What we saw was a significant 20 to 30 per cent reduction in the effective reproduction rate that correlated with that policy.

“It turned the epidemic around from case numbers that were increasing every day to a situation where we could see the numbers were getting back under control.”

Melbourne has entered a fifth Covid-19 lockdown. Picture: NCA NewsWire / Ian Currie

The study used thousands of images from The Age newspaper photo library of Melbourne community settings that showed mask usage rose from 43 per cent before July 22 to 97 per cent afterwards.

It matched “almost perfectly” with a survey led by Monash University, which found that three days before the policy change 44 per cent of people reported “often” or “always” wearing masks compared with 100 per cent “always” four days after they were made mandatory.

Co-lead author Allan Saul said the recent emergence of the Delta variant meant that masks were even more important now than they were 12 months ago.

Former deputy chief health officer Allen Cheng said he regretted not mandating masks earlier. Picture: NCA NewsWire / Sarah Matray

“The introduction of masks was the single most important control measure that took place last year in bringing Melbourne’s second wave under control,” Professor Saul said.

“Masks have a direct impact in stopping people from spreading the virus and they stop other people from getting the virus if they’re in an area where it’s been spread.”

Speaking on ABC radio on Wednesday, former Victorian deputy chief health officer Allen Cheng said he regretted not mandating masks earlier.

“This time last year we weren’t entirely sure how effective masks were … but clearly it’s something that turned out to be quite good and something we’re still using now,” he said.

During Victoria’s fifth lockdown, due to end at 11.59pm next Tuesday, masks have again been mandated everywhere indoors and outdoors except in your own home and during strenuous exercise.

[e-mail]