How is it transmitted?
Research conducted in the UK, where the variant accounts for 99 per cent of new Covid cases, posits the delta variant is about 60 per cent more transmissible than the Alpha variant which health authorities previously believed to be the dominant one. The concern is also mounting that the delta variant could pose a greater risk of hospitalisation and is more resistant to vaccines, particularly after one dose.
According to Queensland’s chief health officer, Dr Jeannette Young, the delta variant is transmitted even in fleeting encounters. “At the start of this pandemic, I spoke about 15 minutes of close contact being a concern. Now it looks like it’s five to 10 seconds that’s a concern. The risk is so much higher now than it was only a year ago.”
As Professor Nancy Baxter, head of the University of Melbourne’s school of population and global health explains, fleeting contact underlines the airborne nature of the virus, which is deeply concerning for health authorities. “The spread is more likely if you’re close to the person [but] there’s still a potential for virus particles to be in the air, and breathed in by someone passing by,” she said.
What about the vaccine?
Australia’s rollout of the vaccine has been incredibly slow, and as such until the population is nearly all immunised, the ability to protect against a variant that’s highly transmissible will continue to be a difficult task. As Dr Stephen Griffin, a virologist and associate professor at the University of Leeds school of medicine said, “It just speaks to the fact that we really, really must keep cases down at the same time as rolling the vaccines out.”
WHO is urging even fully vaccinated people to continue to exercise caution and wear masks, maintain social distance and practice other safety measures to deal with the delta variant. “The virus is circulating in society, so even if you’ve not got high numbers of deaths, it still causes quite a lot of disruption, people having to isolate, people getting sick, people with long Covid,” said Professor Catherine Noakes.
As Dr Griffin explains, “The ideal scenario is that you build your vaccine wall before you get exposed to variants because that means that even if you do get an outbreak, you’ve got sufficiently few people that are susceptible that the reproduction number never gets above 1, you don’t see an increase in that outbreak.”
He added, “The problem is that we haven’t reached that protective level, and so if you do get infections and cases growing there’s plenty of susceptible people to pass that infection on to. This is sign…that we must go belt and braces in all of this. There’s no point leaving it half done - we can’t ignore children in vaccination campaigns. If we do, then we could end up in a cycle of variants.”
While NSW will continue to be in lockdown for the next two weeks and the rest of Australia on high-alert, trusting in the advice of health officials is paramount. As Dr Meru Sheel, a senior research fellow at the Australian National University, said in an interview with The Guardian, “Of course new variants are going to emerge, and some are going to be more infectious and some are going to be less. The public needs to play their part as the public health measures scale up and down based on those variants. Wash your hands, stay at home if you’re unwell, only go to get tested. Wear your mask, get your vaccine if you’re eligible.”