A fresh outbreak of infections in Australia's Victoria state eased further, while the country agreed a deal to secure a potential Covid-19 vaccine that it plans to roll out cost-free to citizens.
Australia has signed a deal with British drugmaker AstraZeneca to produce and distribute enough doses of a potential coronavirus vaccine for its population of 25 million, Prime Minister Scott Morrison said.
"Should we be in a position for the trials to be successful, we would hope that this would be made available early next year. If it can be done sooner than that, great," Mr Morrison said.
All Australians will be offered doses but a medical panel will determine the priority list of vaccine recipients.
"Naturally you would be focusing on the most vulnerable, the elderly, health workers, people with disabilities in terms of the speed of roll out," Health Minister Greg Hunt told Sky News.
Health authorities would also have to take into account where the highest risk of transmission is and how the vaccine works in different age groups when deciding who should get it first, Victoria's chief health officer Brett Sutton said.
"If it does work and it's 80 to 90% effective, then absolutely it will be a game changer," Mr Sutton said, although he cautioned that broad testing was still at a preliminary stage. "So we shouldn't hang our hats on a single vaccine."
AstraZeneca last month said good data was coming in so far on its vaccine for Covid-19, already in large-scale human trial sand widely seen as the front-runner in the race for a vaccine against the novel coronavirus.
The vaccine, called AZD1222, was developed by Britain's University of Oxford and licensed to AstraZeneca.
Mr Morrison said Australia was also looking for other vaccine deals, including with the University of Queensland and its partner, Australian firm CSL Ltd.
CSL estimates first doses of the University of Queensland vaccine will be available for emergency use by the middle of2021, Chief Executive Paul Perrault told reporters.
CSL said its first priority would be manufacturing the UQ vaccine, but it was also in talks to help AstraZeneca manufacture its vaccine.
Mr Morrison said Australia is also talking to its Pacific neighbours, including Indonesia, Papua New Guinea and Fiji, about supplying the vaccine.
A flare-up in infections in Australia's second most populous state of Victoria forced authorities two weeks ago to impose a nightly curfew and shut large parts of the state's economy.
The state has seen a slowdown in new cases in recent days, allaying fears of a nationwide second wave.
There were 12 deaths and 216 new cases in the past 24 hours, down from more than 700 infections two weeks ago. There were just 12 new cases in three other states.
Despite the surge in the past month, Australia has avoided the high casualties of other nations with just under 24,000infections and 450 deaths from the virus.
'Test-and-trace' crucial but won't beat coronavirus alone: study
Testing for Covid-19 and tracing the prior contacts of those found to be infected are crucial measures for slowing the disease's spread, but inadequate unless combined with other measures, researchers said.
By itself, the test-and-trace approach can reduce the virus' reproduction rate, or R number, by 26%, they reported in The Lancet Infectious Diseases, using mathematical models to examine data from previously published studies.
The reproduction rate measures the number of people in a population, on average, infected by each person carrying the virus.
Anything above "1" means the disease is continuing to expand; below that threshold, it will eventually peter out.
Some countries that brought the spread of Covid-19 under control but are now struggling to prevent a resurgence have R numbers well above 1.
But the new finding comes with a caveat, said lead author Nicholas Grassly, a professor at Imperial College's School of Public Health.
"Our results show that test and trace can help reduce the R number but needs to be carried out effectively and quickly to do so," he said in a statement.
Concretely, that means immediate testing with the onset of symptoms and results within 24 hours; the quarantine of contacts, also within 24 hours; and the identification of 80% of cases and contacts.
Very few countries - notably South Korea, Taiwan and Germany - have come close to staying within these guidelines, and most are still falling well short.
Even if nations do adhere to these guidelines, it will still not be enough to bring the infection rate down sufficiently by itself, the new study concludes.
"Test and trace alone won't be enough to control transmission in most communities, and other measures alongside will be needed to bring the R number below 1," said Prof Grassly.
Weekly screening of high-risk groups such as health and social-care workers - regardless of whether they have symptoms or not - can reduce transmission by an additional 23%, his team found.
Experts are still unsure as to what percentage of a population must be immune - a threshold known as "herd immunity" - to prevent the virus from continuing to spread.
Estimates range from below 50 to 70%.
It is possible that some of the hardest hit regions - New York City, northern Italy - may be close to these levels, but at a national scale the numbers are still far lower, probably barely in double digits.
WHO emergencies director Dr Michael Ryan said yesterday that the planet was "nowhere close to the levels of immunity required to stop this disease".
People should "not live in hope of herd immunity being our salvation. Right now, that is not a solution," he added.
The novel coronavirus has killed nearly 775,000 people and infected almost 22 million since the outbreak emerged in China last December, according to a tally from official sources compiled by AFP.
German institute says coronavirus vaccinations could start in early 2021
The head of Germany's vaccines regulator said some groups of people living in Germany could be vaccinated early next year against the coronavirus.
More than half a dozen drug makers around the world are conducting advanced clinical trials, each with tens of thousands of participants, and several expect to know if their Covid-19 vaccines work and are safe by the end of this year.
Klaus Cichutek, head of the Paul Ehrlich Institut, told the Funke group of newspapers that data from Phase I and Phase II trials showed some vaccines triggered an immune response against the coronavirus.
"If data from Phase III trials shows the vaccines are effective and safe, the first vaccines could be approved at the beginning of the year, possibly with conditions attached," he said.
"Based on assurances from manufacturers, the first doses for people in Germany will be available at that time, in accordance with the priorities set by the Standing Committee on Vaccination," he said, referring to the group that makes recommendations for the use of licensed vaccines in Germany.
Infections in Germany have risen in recent weeks and data from the Robert Koch Institute (RKI) for infectious diseases showed the number of confirmed coronavirus cases climbing by 1,510 to 226,914.
