Shares have slipped on the Australian market after overseas worries about coronavirus lockdowns re-emerged, and doubt was cast on a vaccine candidate.

The S&P/ASX200 benchmark index was down 23.4 points, or 0.35 per cent, to 6613.0 at 1200 AEDT on Friday.

The All Ordinaries dropped 23.1 points, or 0.33 per cent, to 6825.7.

Most sectors were lower, and energy took the biggest hit, down 1.64 per cent.

Financials was lower by 0.65 per cent and materials slipped 0.3 per cent.

US markets were closed for the Thanksgiving holiday, while European markets finished little changed or lower.

Cases of COVID-19 continue to soar around the world, and British drugmaker AstraZeneca’s coronavirus drug is facing scrutiny.

Several scientists have raised doubts about claims the shot was 90 per cent effective in a sub-group of trial participants who, by error, received a half dose followed by a full dose.

AstraZeneca, Pfizer and Oxford University have all this month claimed to have vaccines in development which are more than 90 per cent effective. The promising test results have buoyed investors on global markets.

Meanwhile, US President Donald Trump says he will leave the White House if the Electoral College votes for president-elect Joe Biden.

It’s the closest Mr Trump has come to conceding the November 3 election, and should give investors more hope for a smooth transition of power.

In Australia, Victoria has eliminated coronavirus after four weeks without a new case.

Victoria had 7880 active cases on August 11, but months of strict restrictions on movement have stopped the spread.

On the ASX, shares in Bega Cheese bounced 9.71 per cent to $5.46 after the company raised $284 million from a placement and share sale to financial institutions.

The fundraising will help Bega buy Lion Dairy & Drinks for $534 million, announced on Thursday.

A share sale for retail investors will be held in December.

Travel group Helloworld is losing up to $2 million per month amid the pandemic, but company bosses expect trade will improve early next year.

Chief executive Andrew Burnes said he expected underlying losses of between $1.5 million and $2 million for the remainder of the financial year.

However, he was hopeful that all states and territories will be open for travel early next year and there may be more travel between Australian and New Zealand.

Shares were down 3.59 per cent to $2.95.

Oil Search will have to find someone else to replace its retiring chief financial officer Stephen Gardiner.

The company’s chief financial officer designate, Ayten Saridas, who was to replace Mr Gardiner, has opted to leave.

Mr Gardiner will continue until May 31 to help Oil Search find a replacement.

Shares were down 3.43 per cent to $3.66.

The big four banks were all lower. ANZ had the biggest drop, 1.24 per cent to $22.96.

In mining, BHP lost 0.99 per cent to $38.82, Rio Tinto shed 0.63 per cent to $102.21 and Fortescue gained 0.67 per cent to $18.66.

The Aussie dollar was buying 73.61 US cents at 1200 AEDT, up slightly from 73.59 US cents at Thursday’s close.