Prof Michie, a member of the Scientific Advisory Group for Emergencies (Sage), told BBC Radio 4's Today programme it was too early to know what should replace the measures when they end, with the coming fortnight being key.
She said: "They're going to be a very challenging two weeks, partly because of the weather, partly because, I think, the promise of a vaccine may be making people feel complacent."
But she said data showed adherence to lockdown rules had been "pretty steady since the summer".
It comes as the UK recorded a further 26,860 Covid cases on Saturday, along with 462 deaths within 28 days of positive test.
Prof Michie said people had to "get their resolve together" and resist any urge to break the rules, in order to maximise the chance of leaving lockdown.
However, she said she was "quite hopeful" after tough measures in Wales and Northern Ireland brought transmission rates down.
It comes after documents released by Sage on Friday, and dated 4 November, warned that a return to the tiered system of coronavirus restrictions in England after lockdown ends could see infections rise again.
A value below 1 means the number of infections is falling.
Dame Anne Johnson, professor of epidemiology at University College London, said the evidence suggested tier three restrictions had brought the R value down but it was not clear if they would get it under 1.
image captionCapt Gopinath launched India's first budget airline in 2003
In the summer of 2005, retired army officer-turned-businessman GR Gopinath announced that he would enable Indians to fly at one rupee or less than a cent.
It was an incredulous sales pitch from the founder of the country's first budget airline.
Air Deccan, his then two-year-old no-frills airline modelled on European budget carriers like EasyJet and Ryanair, had already made flying affordable to millions of Indians. Capt Gopinath's tickets cost half of what competitors charged.
Now his airline introduced "dynamic pricing" where a small number of "early bird" customers could travel at a rupee. Latecomers would pay a higher ticket price, which would still be substantially lower than competitors. Not surprisingly, booking counters were overrun with customers, many of them first-time fliers. Critics howled such pricing methods would wreck the industry.
"The one rupee ticket fired the imagination of the people and quickly became a buzzword," wrote Capt Gopinath in his memoir. He believed his airline had not "only broken the price barrier, but India's caste and class barrier to flying".
A new Tamil film Soorarai Pottru (Praise the Brave), released on Amazon Prime Video this week, celebrates the life of the maverick businessman. Based on Capt Gopinath's memoir, the film is produced by Academy Award winner Guneet Monga.
IMAGE COPYRIGHTAMAZON PRIME VIDEO
image captionTamil star Suriya plays Capt Gopinath in the film
"It's an incredible story about bridging the gap between the have and have-nots. Most Indians were excited when the concept of low-cost flying was introduced by Capt Gopinath," Ms Monga told the BBC. Tamil film star Suriya, who plays the businessman, says, "He revolutionised flying in India by breaking class and economic barriers".
Soorarai Pottru has all the popular tropes of commercial Tamil cinema: song and dance, a focus on breaking caste and class taboos, and much action and melodrama.
But the film also tells the story of how Capt Gopinath found 500 idle airports and airstrips in India to help expand regional connectivity. It shows how his wife chipped in with her money from her small baking business to help him when he was scrambling for funds; and how his friends from the army were his greatest supporters in fulfilling his dream.
"The film is about what Capt Gopinath stood for - equal access and inclusiveness. He often bit more than he could chew, failed in his ventures, went bust, but his never-say-die spirit is infectious", says Suriya.
Reviews have been encouraging. One said the film makes for a "riveting watch" and another said "beneath the inspiring rags-to-riches tale" it film was a solid commentary on caste." Yet another critic found it an "uplifting underdog tale, where victory was hard-fought, and won".
IMAGE COPYRIGHTAMAZON PRIME VIDEO
image captionThe film shows how Capt Gopinath's wife helped him in the business
Capt Gopinath was born to a teacher-farmer father and stay-at-home mother in a remote village in the southern state of Karnataka.
He joined the army and served in the 1971 Bangladesh Liberation War. He retired at 28. Spurred by a "restless spirit" and the help of his friends, he tried his hand in many businesses, including sericulture and hospitality.
"I was a restless soul in my youth and a mad man obsessed with the idea to make wealth accessible to all", Capt Gopinath told the BBC.
His friends told him that it was not enough to dream but to ''sell dreams".
In 1997 he founded a helicopter service as India's first private charter company. The tagline , he recalls, was: "If you show us a spot on the map, we will get you there."
The spark to start a low-cost airline in India came during a holiday in the US in 2000.
At Phoenix, he found the local airport handled 1,000 flights and 100,000 passengers a day. It was difficult to believe that a "back of beyond airport" handled more flights and passengers than all the 40 airports in India put together, he recounted.
The US, he discovered, operated 40,000 commercial flights a day, compared to 420 in India. He did a quick back-of-the envelope calculation: if 5% of the roughly 30 million Indians who travelled by train and bus began flying, that would translate into an eye-popping 530 million air travellers a year. "Even if this number looked huge, it did not mean 530 million different people travelling but 200 million middle-class people travelling two and half times a year, which was not an unimaginable prospect over the next 30 years," he explains.
"I came back to India possessed by the idea that the common man must fly in India too," Capt Gopinath says.
IMAGE COPYRIGHTREUTERS
image captionAir Deccan used a 48-seater aircraft for its first commercial flight in 2003
In August 2003 he founded Air Deccan with a fleet of six 48-seater twin-engine fixed-wing turboprop aircraft, and one flight a day between the southern cities of Hubli and Bangalore.
By 2007, the airline was operating 380 flights a day from 67 airports, many in small towns. The fleet had grown to 45 planes. Twenty five thousand passengers were flying budget every day, up from 2,000 when the airline began. Three million Indians flew at one rupee a ticket.
But Air Deccan struggled to cope with the costs as losses mounted. In 2007 Capt Gopinath sold his company to Kingfisher, owned by alcohol baron Vijay Mallya, who also owned Kingfisher Airlines. Mr Mallya rebranded Air Deccan as Kingfisher Red.
By then other low-cost carriers had entered the market and still dominate it. In 2018, some 140 million Indians flew domestically, mostly on budget carriers.
But Air Deccan is no longer in the skies. In September 2011, Mr Mallya shut down a bleeding Kingfisher Red and eventually his whole business, which went bankrupt.
Mr Mallya "never had the time for the airline," Capt Gopinath told the BBC in 2012. "If he had focused on it - I don't think anyone could have done a better job than him."
"It was sad. But the dream of Air Deccan lives on. The [budget airline] revolution continues," Capt Gopinath says.
image captionJoe Biden, who campaigned in Georgia in October, is the first Democratic presidential candidate to win the state since 1992
US President-elect Joe Biden has won the state of Georgia, the BBC projects, the first Democratic candidate to do so since 1992.
The win solidifies Mr Biden's victory, giving him a total of 306 votes in the electoral college, the system the US uses to choose its president.
President Donald Trump is projected to win North Carolina, reaching 232 votes.
Mr Trump, who has not yet conceded, alluded for the first time to a possible new administration in January.
Looking subdued, the president stopped short of acknowledging his defeat during a briefing of his coronavirus task force at the White House. These were his first public comments on the election since his defeat was projected by US media.
As the country faces growing outbreaks of Covid-19, Mr Trump said he would not impose a lockdown to fight the virus, adding: "Whatever happens in the future, who knows which administration it will be. I guess time will tell."
The president, who did not mention Mr Biden by name, did not take questions from reporters. Pressure is growing on Mr Trump, a Republican, to acknowledge Mr Biden's victory and help prepare the transition from one administration to another.
media captionPresident Trump: "Who knows which administration it will be, I guess time will tell"
The results in Georgia and North Carolina were the last to be projected in the race for the White House. Mr Biden's electoral votes equal the tally Mr Trump achieved in his victory over Hillary Clinton in 2016. At the time Mr Trump referred to it as "a landslide".
President Trump has launched a flurry of legal challenges in key states and levelled unsubstantiated allegations of widespread electoral fraud. But his efforts suffered three setbacks on Friday:
In Arizona, his team dropped a lawsuit seeking a review of ballots cast on Election Day after it became clear his rival's lead was unassailable. The challenge was based on a claim that some legal votes had been rejected
In Michigan, a judge rejected a request by two Republican poll watchers - who had alleged fraud in Wayne County - to block the certification of election results in Detroit
In Philadelphia, Pennsylvania, the Trump campaign's requests to invalidate several batches of mail-in ballots were rejected
A manual recount is to be carried out in Georgia because of the narrow margin between the two candidates, but the Biden team said they did not expect it to change the results there.
Shifting electoral map
Joe Biden did not have to win Georgia or Arizona to secure the White House. His recapturing of the "blue wall" northern industrial states of Wisconsin, Michigan and Pennsylvania by themselves assured his victory.
The former vice-president's success in these Sun Belt states - the first time a Democrat has won either in decades - suggests, however, that Democrats may be clearing a new path to presidential success in future elections.
If so, it would make Democrats less dependent on the kind of non-college-educated white voters in those northern battlegrounds that, given Donald Trump's appeal, may be trending toward the Republicans. It was educated suburban voters, as well as traditionally Democratic ethnic minorities, that delivered Georgia and Arizona to Mr Biden.
It is not all good news for the Democrats, however. Donald Trump did win North Carolina - another southern swing state - even though it was carried by Barack Obama in 2008.
The electoral map is shifting, and the parties will have to adjust their strategies accordingly. In the meantime, Georgia - which has two January run-off elections that will decide control of the US Senate - will take centre stage in the months ahead. Joe Biden's narrow victory there all but assures it will be a hotly contested battle.
Biden team urge access to briefings
The General Services Administration (GSA), the government agency tasked with beginning the transition process, has yet to recognise Mr Biden and his running mate Kamala Harris as winners.
Meanwhile, the Biden team have not been given access to classified security briefings, federal agencies and funding needed to ensure a smooth transition of power. Biden spokesperson Jen Psaki said this lack of access could affect Mr Biden's ability to govern.
"You need real-time information to deal with crises of the moment," she said, highlighting the impact of the pandemic. "It's imperative that our team and our experts have that access".
media captionObama: Claims of election fraud are "delegitimising" democracy
Earlier, a group of more than 150 former national security officials urged the GSA to officially recognise Mr Biden so that they could access "pressing national security issues". A small but growing number of Republicans are also backing calls for the president-elect to be given daily intelligence briefings.
What is Trump saying?
The president continues to dispute the election result. A tweet on Saturday questioned the checks on mail-in ballots in Georgia, saying: "Expose the crime!"
It was the latest in a slew of tweets backing his claims of widespread election fraud, although he has provided no evidence.
He also suggested he might join his supporters at a rally planned in Washington on Saturday.
The statement from the Election Infrastructure Government Co-ordinating Council was released after Mr Trump tweeted that voting software used in 28 states had deleted millions of votes for him, but presented no evidence.
The claim appeared to originate from the obscure TV network One America News (OANN) and was flagged by Twitter as disputed.
On Friday, White House spokeswoman Kayleigh McEnany told Fox News: "President Trump believes he will be President Trump, have a second term."
