President Donald Trump's controversial coronavirus adviser resigned Monday, while hopes for a first wave of vaccinations before the end of 2020 received a further boost with an announcement from US firm Moderna.

Scott Atlas, a favored coronavirus adviser of the US president, who tweeted in October "Masks work? NO," has submitted his resignation, effective as of December 1, Fox News reported.

The first of Moderna's two doses could be injected into the arms of millions of Americans by the middle of December
The first of Moderna's two doses could be injected into the arms of millions of Americans by the middle of December AFP / JOEL SAGET

Lacking relevant experience or qualifications in public health or infectious disease, he also called in November for people in Michigan to "rise up" against Covid-19 measures.

Atlas stepped down as hopes rose for a first wave of vaccinations before the end of the year after Moderna said it was filing for emergency authorization of its vaccine in the United States and Europe.

After top US scientists warned Americans to brace for a "surge superimposed on the surge," Moderna reported full results had confirmed a high efficacy estimated at 94.1 percent.

How Moderna's vaccine uses genetic information from SARS-CoV-2 to stimulate the body's immune response. Moderna said it would file requests for use of its vaccine in the US and Europe on November 30
How Moderna's vaccine uses genetic information from SARS-CoV-2 to stimulate the body's immune response. Moderna said it would file requests for use of its vaccine in the US and Europe on November 30 AFP / John SAEKI

It was set to join American pharmaceutical maker Pfizer and Germany's BioNTech, which applied for similar approvals last week, and have predicted their vaccine could be greenlit in the US shortly after December 10.

If the US Food and Drug Administration agrees Moderna's product is safe and effective, the first of the drug's two doses could be injected into the arms of millions of Americans by the middle of December.

Sri Lankan prison guards shot dead eight inmates and wounded at least 71 others in a riot sparked by anger over rising coronavirus infections
Sri Lankan prison guards shot dead eight inmates and wounded at least 71 others in a riot sparked by anger over rising coronavirus infections AFP / LAKRUWAN WANNIARACHCHI

Health Secretary Alex Azar told CBS News: "We could be seeing both of these vaccines out and getting into people's arms before Christmas."

Co-developed with the US National Institutes of Health, the jabs were generally well tolerated, with the most common side effects including injection site pain, fatigue, muscle pain, joint pain and headache.

Moderna expects to have approximately 20 million doses of the vaccine available in the US by the end of 2020, and between 500 million to a billion doses globally in 2021.

Britain is still battling to bring down the daily deaths and infections with a variety of curbs, lockdowns and tests
Britain is still battling to bring down the daily deaths and infections with a variety of curbs, lockdowns and tests AFP / OLI SCARFF

The news came after leading US scientist Anthony Fauci voiced his fears as millions of travelers returned home after the Thanksgiving holiday.

The United States is the worst-affected country, with more than 267,000 Covid-19 deaths, and the Trump administration has issued conflicting messages on mask-wearing, travel and the danger posed by the virus.

Hong Kong is experiencing a spike in cases of the Covid-19 coronavirus
Hong Kong is experiencing a spike in cases of the Covid-19 coronavirus AFP / Anthony WALLACE

"What we expect, unfortunately, as we go for the next couple of weeks into December is that we might see a surge superimposed on the surge we are already in," Fauci said Sunday.

Top US scientist Anthony Fauci voiced his fears for a virus surge as millions of travelers returned home after the Thanksgiving holiday
Top US scientist Anthony Fauci voiced his fears for a virus surge as millions of travelers returned home after the Thanksgiving holiday AFPTV / Derek HENKLE

More than 1.4 million people have died worldwide since the outbreak in China last December, according to a tally from official sources compiled by AFP.

The World Health Organization (WHO) insisted Monday it was doing everything possible to find the animal origins of the virus, although it hasn't yet sent a full team of expert investigators to China.

Observers have voiced concern the agency has bowed to Chinese pressure and dragged its feet over the investigation, but WHO chief Tedros Adhanom Ghebreyesus hit back and urged critics to stop "politicizing" the issue.

At a briefing, Tedros added he was alarmed over a rapid worsening of the Covid-19 situations in Brazil and Mexico, urging them to be "very serious" about halting the spread.

Europe meanwhile is still battling to lower the daily toll of death and infection with a variety of curbs, lockdowns and tests after fatalities topped 400,000 at the weekend.

Turkish president Recep Tayyip Erdogan announced a total weekend lockdown and a curfew for the rest of the week.

In Asia, Hong Kong on Monday announced social distancing measures at some of the strictest levels in the city since the start of the pandemic, as authorities battle a fourth wave of infections.

"This new wave of Covid-19 has hit Hong Kong very quickly," chief executive Carrie Lam said.

Anger over rising infection numbers sparked a riot in a Sri Lankan prison where guards shot dead eight inmates and wounded at least 71 others.

However, Australia's success against the pandemic saw international students arrive for the first time since it shut its borders in March, with a charter flight touching down in Darwin on Monday.

The situation in former global epicenter New York remains precarious, with Governor Andrew Cuomo warning small gatherings are now responsible for 65 percent of the spread.

"We are now worried about overwhelming the hospital system," Cuomo said, warning a new lockdown could be needed.

California Governor Gavin Newsom said his state's hospital intensive care units could be overloaded in just a couple weeks.

Covid risk across most of the US is now considered "critical" and more than 93,000 people are hospitalized, according to the Covid Tracking Project.

Scientists estimate around 70 percent of the population will need to be vaccinated to bring an end to the outbreak, and this may not be achievable until the second half of next year.