Anthony Albanese will be forced to campaign from home after the opposition leader tested positive to COVID-19.

The Labor leader returned a positive result following a routine PCR test on Thursday afternoon, but is not showing symptoms.

Mr Albanese was due to fly out on Friday from Sydney to campaign in Western Australia.

He will instead isolate at his home in Sydney for seven days.

"While at home I will continue my responsibilities as alternative prime minister and will be fighting for a better future for all Australians," he said.

"I am grateful to know that I will have access to the world's best health care if I need it, because of Medicare."

Prime Minister Scott Morrison sent best wishes to his election rival.

"Everyone's experience with COVID is different and as Labor's campaign continues, I hope he does not experience any serious symptoms," Mr Morrison said on Twitter.

Labor campaign heads had prepared for the possibility Mr Albanese might test positive, with opposition frontbenchers set to play an expanded role over the coming days.

Mr Albanese is likely to still conduct press conferences virtually, should he not be experiencing COVID-19 symptoms.

The opposition leader had spent Thursday campaigning on the NSW south coast and in Sydney.

On Wednesday evening he spent time with Mr Morrison in Brisbane when the two leaders met for the first election debate.

Labor's campaign launch, set down for May 1 in Perth, is expected to go ahead as planned.

Mr Morrison will still be on the campaign trail on Friday, starting day 12 in Queensland, where he will announce a $428 million upgrade to four defence force air bases.

Construction at Amberley, Richmond, Pearce and HMAS Albatross would create 600 new jobs, with the upgrades to be completed by 2024, News Corp reports.

The Australian Electoral Commission will also conduct the ballot draws at midday on Friday for all lower and upper house seats.

The electoral commissioner confirmed 96.8 per cent of the eligible population will be able to cast their ballot when Australia goes to the polls on May 21.

More than 17.2 million people are on the electoral roll, an increase of more than 804,000 since the last election in 2019.

Electoral commissioner Tom Rogers said more than 100,000 people were added to the electoral roll in the last week before the rolls closed.

"Around 80,000 young Australians aged 18-24 jumped online in the week after the election was announced, resulting in 88.1 per cent of that age cohort ready to have their say this May," he said.

© AAP 2022

Elon Musk has secured $US46.5 billion ($A62.5 billion) in funding to buy Twitter Inc and is considering a tender offer for its shares, a filing with US regulators shows.

Musk himself has committed to put up $US33.5 billion, which will include $US21 billion of equity and $US12.5 billion of margin loans, to finance the transaction.

Banks, including Morgan Stanley, have agreed to provide another $US13 billion in debt secured against Twitter itself, according to the filing.

Twitter was not immediately available for comment.

Musk "is seeking to negotiate a definitive agreement for the acquisition of Twitter... and is prepared to begin such negotiations immediately," the documents say.

Musk's latest move comes after Twitter failed to respond to his offer and adopted a "poison pill" to thwart the billionaire's effort to buy the social media platform for $US43 billion.

Musk, a self-described "free speech absolutist," has said the social media company needs to be taken private to grow and become a platform for free speech.

The offer from Musk, who is the second-largest shareholder of Twitter, has drawn private equity interest in participating in a deal for Twitter, Reuters reported, citing people familiar with the matter.

Apollo Global Management Inc is considering ways it can provide financing to any deal and is open to working with Musk or any other bidder while Thoma Bravo has informed Twitter that it is exploring the possibility of putting together a bid.

Musk, an active Twitter user with more than 80 million followers on the platform, has made of number of announcements on the platform including some that have landed him in hot water with US regulators.

In 2018, Musk tweeted he had "funding secured" to take Tesla Inc private for $US420 per share - a move that led to millions of dollars in fines and him being forced to step down as chairman of the electric car company to resolve claims from the US securities regulator that he defrauded investors.

with AP

© RAW 2022

The Queen is marking her 96th birthday privately, retreating to the Sandringham estate in eastern England that has offered the monarch and her late husband, Prince Philip, a refuge from the affairs of state.

She is expected to spend the day at the estate's Wood Farm cottage, a personal sanctuary where she also spent her first Christmas since Philip's death in April 2021.

Philip loved the cottage, in part because it is close to the sea, she said in February when hosting a rare public event at Sandringham.

"The Queen's approach to birthdays very much embodies her 'keep calm and carry on' attitude," Emily Nash, the royal editor at HELLO! magazine, said.

"She doesn't like a fuss."

This birthday comes during the Queen's Platinum Jubilee year, marking her 70 years on the throne.

It will be marked on Thursday with a gun salute in London's Hyde Park and the release of a new photograph showing Britain's longest-serving monarch with two white ponies at Windsor Castle.

A Barbie doll dressed in an ivory gown with a blue sash was also released to mark the jubilee celebrations.

"An inspiration to so many across the UK, the Commonwealth and the world, it's particularly special to be celebrating in this Platinum Jubilee year," a message from the Queen's grandson Prince William and his wife Kate said on Twitter.

While Thursday will be relatively low-key, public celebrations will take place in June with four days of festivities.

The day marks yet another milestone in a tumultuous period for the monarch, who has sought to cement the future of the monarchy amid signs of her age and controversy in the family.

After recovering from a bout of COVID-19 earlier this year, the Queen's public appearances have been limited by unspecified "mobility issues".

Prince Andrew's multi-million pound settlement with a woman who accused him of sexual exploitation also caused unwanted headlines for the royal family.

But the Queen got an early birthday treat last week, when grandson Prince Harry and his wife Meghan, the Duchess of Sussex, paid her a joint visit for the first time since they stepped away from frontline royal duties and moved to California in 2020.

Harry, in an interview with NBC, said his grandmother was "on great form", though he added he wanted to make sure she was "protected" and had "the right people around her".

The Queen has spent much of the past two years at Windsor Castle, west of London, where she took refuge during the pandemic.

- with Reuters

© AP 2022

Parents of NSW children aged between six months and five years are urged to book them in for a flu shot, with almost two in 10 catching the influenza virus as the autumn chill hits.

Young children make up a higher proportion of flu cases compared with two years ago, acting executive director of Health Protection NSW Vicky Sheppeard said.

"Almost two in 10 flu notifications (17 per cent) in March were kids aged under five, compared with one in 10 (10 per cent) for the same period in 2019," she said on Thursday.

With COVID-19 social restrictions relaxed and travel across international borders in full swing, more people of all ages will be at risk of influenza than in the past two years, Dr Sheppeard warned.

Vaccination for pregnant mothers provides immunity to infants in the early months of life.

Vaccinations are available through GPs for those aged six months and over and additionally through pharmacies for people aged 10 and over.

Those considered to be at higher risk of severe illness from the flu include Aboriginal and Torres Strait Islander children as well as pregnant women and people over 65.

Others at risk include people with serious health conditions such as severe asthma, diabetes, cancer, immune disorders, obesity, kidney, heart, lung or liver disease.

© AAP 2022