Is the worst over? Encouraging chart shows ‘ray of hope’ that vaccination is starting to flatten the curve in NSW – as the reproductive rate drops below one for the first time since outbreak began
- Covid transmission curve begins to flatten as reproductive rate falls below one
- Professor Adrian Esterman has been tracking reproductive (Reff) rate since June
- NSW hit 1,405 cases but Professor Esterman suggests it may be a positive trend
- A Reff rate below 1 indicates the end of an outbreak as transmission peters out
Covid cases could soon hit its peak as the reproductive rate of the virus falls below one for the first time since the NSW outbreak began – bringing locked-down Sydneysiders one step closer to freedom.
As NSW recorded 1,405 cases on Thursday Professor Adrian Esterman, an epidemiologist at the University of South Australia, indicated it may be a sign of a positive trend emerging.
‘Another 1405 cases for NSW today. The five day moving average has dropped again to 1305, and the Reff has dropped below one for the first time since the outbreak started. It is starting to look very peakish,’ wrote Professor Esterman on Twitter.
The reproductive rate indicates how many people each infected person passes the virus onto.
An effective reproductive rate or ‘Reff’ is a more complex form of modelling which takes into account population immunity, hospitalisations and social distancing.
Professor Adrian Esterman has been tracking NSW and Victoria’s Reff rate since the beginning of the outbreak in June
Professor Esterman believes the decline in the reproductive rate of infections is due to higher vaccination rates
According to data collated by Prof Esterman, which is available to view online, the Reff recorded on Saturday in NSW was 1.21 and has been steadily declining since.
It reached 1.17 on Sunday, 1.13 on Monday, 1.08 on Tuesday and 1.01 on Wednesday before dropping to 0.96 on Thursday.
Based on modelling he is following from Chris Billington, a research fellow in physics at the University of Melbourne, Professor Esterman predicts case numbers – based on the declining Reff rate – will peak to 1,500 by September 15.
The sooner Covid cases reach its peak and the Reff rate declines – and stays – below one the closer Sydneysiders will edge towards freedom.
Dr Kerry chant said vaccination rates were promising but warned Sydneysiders who are ‘starting to see the sun shine’ and ‘rays of hope’ to a lockdown end, that it was up to the community to put in the hard yards
The encouraging data offers a ray of hope for Sydneysiders who endure their second month in lockdown.
NSW chief health officer Dr Kerry Chant said the state’s vaccination rates were likely to hit 80 per cent by Monday if it continues at its current pace.
‘I’m really very excited by the way that the community is embracing immunisation. We’ll get to 80% by Monday or Tuesday, and you can hold me to that,’ Dr Chant said during Thursday’s daily Covid press conference.
‘But, please, community members, can you keep coming forward so I can stick to that?’
With vaccination now available for all 12 to 15-year-olds from September 13 and doses of Moderna arriving later in the month, the chief health officer said it gave her a ‘degree of confidence.’
But Dr Chant warned Sydneysiders who are ‘starting to see the sun shine’ and ‘rays of hope’ to a lockdown end, that it was up to the community to put in the hard yards.
‘Please do not take risks while we’re in this period,’ she warned.
‘We do not need any super-spreading events. We do not need any seeding in the regions. We just do not need anything else as we work to drive the case numbers down and leverage our response off the back of the vaccine uptake that we’ve seen.’