The Australian COVID experience
This week’s expert:
Prof Tony Blakely, Epidemiologist and Public Health Medicine Specialist, University of Melbourne
Drawn from Dr David Lim’s interview with Professor Tony Blakely on the Healthed Podcast ‘Going Viral’.
What we’ve learned so far:
• Hard lockdowns need to be implemented early in an outbreak if they are going to work. Victoria did not enforce the hard lockdown early enough in the most recent outbreak allowing community spread
• The recent outbreak in New Zealand is not evidence that an elimination strategy doesn’t work. The New Zealand authorities had in place a plan should new cases occur, which they have implemented (Auckland on stage 3 level restrictions and the rest of the country on stage 2). They are still pursuing an elimination strategy
• The false-negative rate of the current PCR COVID-19 testing is between 10-20%.
• A strategy of suppression is more likely to be successful if there is efficient and effective contact tracing in place. Contact tracing services can get overwhelmed with high case numbers (eg >200 new cases/day) and therefore can’t be seen as an effective tool in controlling an outbreak past a certain point. Currently NSW, with its reliance on contact tracing and low level restrictions appears has very few new cases and appears on track to achieve elimination.
• Lockdown fatigue is likely to occur in Victoria as a result of the extended lockdown period. Should control of the outbreak not be achieved in the next few weeks, the people’s morale and economic consequences of the lockdown might see the state opt for a policy of suppression rather than elimination. Modelling for this possibility is currently underway
• Should Victoria opt for a suppression policy rather than elimination, it will be out of synch with all the other states and territories. This is likely to have significant implications for interstate travel.
• The success of making the wearing of facemasks mandatory in Victoria should be an example to the rest of the country. Face masks should be made mandatory especially for people using public transport or attending supermarkets.
• When new case numbers are very low, it is best to look at weekly numbers (rather than daily numbers) before making inferences about control of the virus.
• Recent evidence suggests we should have an effective, safe vaccine against COVID-19 within a year
• Concerns about the safety of a vaccine are unlikely to be valid. Before a vaccine becomes available it will have to have passed phase 3 trials, where it will have been given to 10,000 – 20,000 people to have its full safety profile assessed.
• Once a vaccine becomes available, the priority will be to vaccinate those populations most at risk. Countries such as Brazil and India, with their high rates of new cases will and should be the first to receive supplies of the vaccine. It is likely Australia might have to wait if there is a delay in production.