The top infectious disease expert in the US, Dr Anthony Fauci, has said Americans should prepare for a "surge upon a surge" in coronavirus cases as millions of travellers return home after Thursday's Thanksgiving holiday.

The trend is ominous, Dr Fauci and other government scientists said, with the Christmas holidays sure to bring more travel and family gatherings.

The Pfizer and Moderna vaccines, both said to be safe and 95% effective, have introduced a glimmer of hope after months of gloomy news.

But, like Dr Fauci and the other scientists, he expressed grave concerns about the months ahead.

Foreign students arrive in Australia for first time since virus closure.

International students have arrived in Australia for the first time since the country shut its borders to curb coronavirus in March, with a charter flight touching down in Darwin.

A plane chartered by Charles Darwin University (CDU) carrying 63 international students arrived in the northern city of Darwin as part of a pilot programme aimed at kickstarting the higher education industry.

The students - from mainland China, Hong Kong, Japan, Vietnam and Indonesia - travelled to Singapore to catch the flight and will now spend 14 days in a government quarantine facility.

The mix of new and continuing students are enrolled across a range of undergraduate and postgraduate courses including law, nursing and engineering.

Lobby group Universities Australia said in June that the sector could lose US$11 billion as a result of the border closure.

Many international students also remain stuck in Australia, and some are relying on charities for food handouts after they were excluded from support packages.

The financial hub has maintained bans on large group gatherings for much of the year and has shuttered various industries when cases have spiked.