Australia is trying its utmost to contain fresh outbreaks of COVID-19.
Most of the country has entered into new snap lockdowns, as cases of the delta variant of SARS-CoV-2 spread across several cities. Darwin, Perth, and Brisbane emerged from lockdowns over the weekend.
However, 5.3 million people in Sydney have been on lockdown for a week. The state of New South Wales (NSW), of which Sydney is the capital, also reported 35 locally acquired new cases on Friday and the following Monday, recording its highest number of daily cases for 2021.
This upward trend prompted the government to extend the lockdown to July 16.
To combat the slow uptake of the embattled Oxford-AstraZeneca vaccine, the government also recently made it available to anyone aged under 60 years, and established mass immunization hubs.
But is that enough to explain why there are sudden outbreaks?
What Australia has done so far
Australia’s approach to the COVID-19 pandemic has differed from that of most Western states or the northern hemisphere in general.
Australia has handled the pandemic better than many other nations, experiencing a relatively low rate of infections and recording comparatively fewer deaths. It has owed this success to border closures, strict lockdowns, and rigorous contact tracing.
Since March 2020, the country has largely prohibited overseas arrivals, except for returning Australians and residents and those with exemptions, including visitors from New Zealand. However, 14-day hotel quarantines were mandated for all other international arrivals.
The country was in the process of gradually reopening its borders, with reports of a travel bubble for the United Kingdom or the United States starting to circulate in the media. However, recent outbreaks of the delta variant have prompted the government to keep measures in place and ease at a slower, more controlled pace.
Last week, the government announced that the number of international arrivals would be halved, to 3,000 people per week, starting from July 14.
Fewer than 31,000 reported cases and 910 deaths since the beginning of the pandemic have been a testament to Australia’s successful COVID-19 strategy, which has been termed “COVID zero.”
Just two new COVID-19 cases were enough for Brisbane, the capital of Queensland, to go into a 3-day lockdown.
Speaking to Medical News Today, virologist Dr. Ian Mackay from The University of Queensland said this success stems from their quick response.
“They were prepared, had testing in place, and created guidelines and response plans that saved many lives. Some say Australia has been lucky, but that ignores the enormous amount of behind-the-scenes collaborative work that has gone into keeping Australia safe.”
Calling Australia an “international model” in the fight against the pandemic, Dr. William Schaffner, professor of medicine at the Division of Infectious Diseases at Vanderbilt University in Nashville, TN, said its COVID zero policy was aspirational.
“It sets an expectation around which the population can rally. It puts the population on notice that all will need to contribute, and it informs them that vigorous national public health policies will be employed.”
In comparison, Prof. Schaffner told MNT, the U.S. has not been as successful.
“I see Australia and the U.S. representing the opposite ends of the spectrum of the early responses to COVID-19. Australia acknowledged early the potential gravity of the problem, designed a national response, saw this as a public health rather than a political issue, and communicated clearly to the population.”
However, with the emergence of the delta variant, zero cases may not be a realistic target. Prof. Adrian Esterman, a professor of biostatistics and epidemiology at the University of South Australia in Adelaide, agrees.
“The original lockdown in 2020, in fact, did get us down to zero cases. As for the future, we will have to live with occasional outbreaks, and a suppression approach is more realistic.”
And although Australia’s response to the initial epidemic was praised as one of the best, progress has started to go downhill.
Prof. Esterman said there were three major problems with Australia’s current approach.
It refused to build fit-for-purpose quarantine stations and relied instead on leaky quarantine hotels in the middle of cities. It relied heavily on the AstraZeneca vaccine with not enough early orders for the others. And finally, it insisted that states and territories take the lead when there should be a national approach.
This has led to interstate differences in contact tracing and quarantine systems, lockdowns, and mask-wearing practices, much like in the U.S.
Delta variant changing the fight
Data from the U.K. suggest the delta variant is around
This makes outbreaks more likely to occur across the globe. According to the World Health Organization (WHO), as of June 29, the delta variant is present in
Australia, however, is not new to the more infectious delta variant. It has dealt with several clusters and effectively managed cases, except for the recent outbreak in NSW.
The state of NSW, which is the country’s most populous, remains to grapple with an outbreak that has grown to 347 cases as of Tuesday, July 6.
These new outbreaks can be traced back to a handful of cases where travelers with a SARS-CoV-2 infection breached hotel quarantines, or households flouted social distancing rules.
One such case was a birthday party in Sydney on June 19, where 24 people contracted SARS-CoV-2. Six fully vaccinated healthcare workers and one partly vaccinated attendee did not contract the virus.
“Other small outbreaks related to the delta variant have been successfully squashed using rapid sharp lockdowns. NSW has always been reluctant to go into lockdown because of its excellent contact tracing system. This has always worked in the past but did not work for the delta variant,” Prof. Esterman told MNT.
He said the slow vaccine rollout was a major concern, given the increased transmissibility of the delta variant.
Prof. Schaffner also believes vaccines will be the best defense.
“Australia has implemented containment responses really well and, perhaps because they were so successful, has been less vigorous in promoting COVID-19 vaccination. Thus, when imported COVID-19 manages to escape the containment measures, it can spread readily, because vaccination rates are low.”
– Prof. William Schaffner
At 1.8 million, just over 7% of the Australian population have received both doses of COVID-19 vaccines.
While acknowledging that low vaccination rates do not help, Dr. Mackay said that higher vaccination rates were not a guarantee on their own either.
“In countries with much higher but stalled rates, [we see that] SARS-CoV-2 can still easily spread and cause hospitalization among those who remain unvaccinated,” he told MNT.
Dr. Mackay said the best way to remain safe, as Australia has shown, is to use layers of risk prevention, referring to his now-famous Swiss cheese analogy.
The analogy paints each cheese slice as a layer of protection, such as mask-wearing, social distancing, or vaccination. Each layer has holes or an escape route for the virus. But when combined with multiple layers, the overall risk drastically reduces, as each layer blocks the spread bit by bit.
Prof. Esterman said other countries that have fully vaccinated a high proportion of their populations will be able to get away with fewer restrictions.
“Otherwise, Australia has shown that short, sharp lockdowns work against the delta variant,” he added.
With regard to the issue of vaccine efficacy against the delta variant, Prof. Schaffner said it has yet to be determined how effective each shot is, although mRNA vaccines appear to be “quite effective.”
He pointed out, however, that “over 90% of patients admitted to hospitals in the U.S. are [either] unvaccinated or incompletely vaccinated.”
“Thus, it is clear that vaccinated persons are being protected and also, sadly, that most of these hospital admissions could have been prevented had those persons taken advantage of the vaccines.”
Obstacles to mass vaccination
Worries about side effects from COVID-19 vaccines have been a major roadblock for Australia.
A survey by the Sydney Morning Herald and research company Resolve Strategic found that close to a third of the population were unlikely to get vaccinated.
The AstraZeneca vaccine has been associated with a rare side effect called thrombosis with thrombocytopenia syndrome, which causes blood clots in different parts of the body and can be fatal.
Despite there being a very low risk of experiencing this side effect, those under 60 years of age have been estimated to have a slightly higher risk.
Two women over the age of 40 years died in Australia from blood clots after receiving the vaccine. This prompted the Australian Technical Advisory Group on Immunisation to recommend the vaccine only to those aged 60 years or older.
Yet last week, Australian Prime Minister Scott Morrison backtracked and said those younger than 60 years old who wish to receive the vaccine could but should speak with a doctor.
Prof. Esterman said this has sowed confusion among the public and contributed to vaccine hesitancy.
“The federal government has made a mess of the decisions around who can get the AstraZeneca [vaccine], constantly changing the advice and messaging and confusing everyone. They have also not done well at explaining to the general public just how small the risk [of blood clots] is. I am sure that this has increased vaccine hesitancy.”
The current formal advice is that the AstraZeneca vaccine is recommended for those aged over 60 years, and the Pfizer vaccine — for those under the age of 60. However, younger adults can receive the former if they are given the green light by a doctor.
Drawing parallels between Australia and the U.S., Prof. Schaffner opined the blood clotting “has certainly dimmed enthusiasm for the similar Johnson & Johnson vaccine in the U.S.”
Prof. Schaffner said that could have, in part, played a role in the current situation in Australia, but added, “Beyond that, the early success in containing the spread of COVID-19 in the general population may have created a sense of complacency, such that COVID-19 vaccination was perceived as less urgent.”
This was reflected in the remarks by Prime Minister Morrison, who said in January that they would remain cautious in the vaccine rollout as they were not in an “emergency situation” like the U.K. was at that time.
“We don’t have to cut corners. We don’t have to take unnecessary risks,” he told local radio 3AW.
Meanwhile, other scientists think the slow rollout is likely due to logistical and communication problems rather than hesitancy about its safety.
Citizens waiting for the Pfizer-BioNTech vaccine have been warned of a monthslong wait. The bulk of the vaccines is expected to arrive in Australia in the last quarter of this year.
The country has had trouble locally manufacturing the AstraZeneca vaccine, for which it had plans of 50 million doses, while running into issues in procuring the Pfizer vaccine, as suppliers cannot meet the surging demand.
Dr. MacKay said:
“Once we have less contentious vaccine supplies, I’m confident Australians will more eagerly roll up their sleeves so they and their loved ones can be protected from serious disease and death due to COVID-19. We just need supplies and good communication to make this happen. Those are the real hurdles to a higher rate of uptake here.”
Until then, scientists recommend taking whatever vaccine has been made available to them.
To the point
Ever since the emergence of the more transmissible delta variant of SARS CoV-2, countries have seen cases sprout rapidly. One of these countries has been Australia.
Rule breakers, such as those attending the house party in Sydney, have been behind some of these outbreaks.
Issues in procuring and manufacturing vaccines — especially the AstraZeneca one, which was the backbone of Australia’s immunization strategy — have put the country behind schedule in fully vaccinating its population. This has partly contributed to the latest situation.
Vaccine hesitancy and a frequent change of advice have also stalled the process.
Experts had been warning that a slow vaccine rollout could endanger the progress Australia recorded over the last few months and that being complacent could fuel fresh clusters.
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