According to epidemiologists, future pandemic modeling in Australia will consider the deadly Delta variant of Covid.
Researchers said Monday that evidence has been presented that suggests that Delta's severity has increased since initial modelling by Doherty Institute.
Professor James McCaw from the University of Melbourne worked with the Doherty Institute to model the spread of Delta. However, it was not clear at that time if infections were more serious than the rapid spread of the virus.
He said that there was no evidence that Delta had worse clinical outcomes than the rest of the world.
Two studies have been published since then that found patients infected by Delta are more likely than those infected from the original virus or Alpha. The first study, which was from Scotland, was published June and the second, from the University of Toronto in Canada, August.
McCaw stated that scientists constantly update their understanding of the evidence. It is now clearer that Delta is more severe. So work and, for example, forecasts of possible hospitalisations, would explain the severity of Delta.
The overseas findings are taken into consideration when Victoria's roadmap for reopening is developed.
Alexandra Martiniuk from the University of Sydney is a professor of epidemiology. She said that both the Canadian and Scottish data were based upon robust health datasets, including national and provincial-wide datasets.
She said that this gives strength to the study findings.
When multiple studies support the same conclusion, science can be more confident in its data. Delta may be causing more severe diseases. It is likely that more rigorous studies will confirm this.
To aid in decision-making, models simulate many scenarios. However, it is important that models consider the possibility of Delta being more severe. When we use modelling to plan for lifting restrictions or anticipating the burden on our healthcare system, it is important that our models account for Delta's increased infectiousness and potential to cause more severe diseases.
The greatest threat to unvaccinated individuals remains, according to the studies. Our University of Toronto study showed a significant reduction in the risk of serious disease and death for both fully and partially vaccinated subjects.
The study revealed that Canada is one of the most vaccinated countries worldwide in terms of SARS-CoV-2 [Covid-19]. This has helped to reduce the potential impact of these VOCs [variants or concern] on the population.
Martiniuk stated that although the inputs to modelling for Australia's reopening changed with new evidence, the majority of advice landed in the exact same place. He said that a combination of high levels and ongoing public health measures was needed.
The University of Melbourne has released new modelling on Tuesday that supports the key finding of the Doherty Report for Reopening: Keeping restrictions light at all times will drastically reduce the need to lockdown.
The country should aim to achieve a 90% vaccination rate in the adult population. This would reduce hospitalisations and deaths by approximately 80% and most likely not require any lockdown.
Professor Tony Blakely of the University of Melbourne has reported that booster vaccines are needed soon to combat the waning immunity of AstraZeneca as well as Pfizer against Delta virus. It recommends that global vaccination be a top priority.
This is good for equity, and it also reduces the risk of new dangerous variants emerging.
Last week, the latest Doherty modeling update was published.