COVID-19 modeller and Director of the University of Sydney’s Centre for Complex Systems Professor Mikhail Prokopenko, Dr Sheryl Chang, Dr Oliver Cliff and Dr Cameron Zachreson have today released updated modelling on pre-print server arXiv that shows Sydney’s current level of social distancing is still inadequate for outbreak control.
The modelling analysed the period between 16-25 July 2021, finding that although the actual incidence growth has reduced from 10 to 3.7 percent, social distancing currently sits at around 60 percent, which is still too low to control the outbreak of Delta.
The study also included an analysis of a progressive vaccination rollout, finding that if even 40 percent of the Greater Sydney population was fully vaccinated by mid-September, a stricter lockdown needs to continue until then to control Delta. In NSW currently only 16.9 percent of the population is fully vaccinated.
“While in the last fortnight social distancing compliance appears to have increased to 60 percent from 40 percent, this level is still inadequate for the control of the Delta outbreak,” said Professor Prokopenko, from the Faculty of Engineering.
“To adequately suppress the outbreak, 70-80 percent of residents in Greater Sydney must comply with social distancing, however we are just not seeing those numbers yet.
“What is most concerning is that our model showed that even when we take into account essential workers, 10-15 percent of the population is still not doing the right thing which means we could be stuck in lockdown for quite a while longer.
“The accelerating vaccination rollout will begin to make a difference in a few months, but at this stage a tight lockdown makes a larger impact and needs to continue.
“The main takeaways are people should continue to stay at home as much as possible, minimise their interactions outside households, and get vaccinated.
“No one wants to be in a position where we are still in a lockdown at Christmas. Australia needs to emerge from this and the only way to do so is to go hard and thoroughly.”