The next two weeks will be “absolutely crucial” in ensuring that England’s coronavirus lockdown ends as planned on 2 December, a government scientific adviser has said. Prof Susan Michie, who is a member of the government’s Covid-19 behavioural science team, a subgroup of the Scientific Advisory Group for Emergencies (Sage), said the country was entering a “very challenging” fortnight. She also said the development of an effective vaccine should not make people complacent about the spread of coronavirus in England. “I think the next two weeks is going to be absolutely crucial. Partly because of the weather, partly because I think the promise of a vaccine may be making people feel complacent,” she told BBC Radio 4’s Today programme on Saturday. Michie said a vaccine was unlikely to be distributed until the end of the year, or beginning of 2021, meaning it would make no difference to the current second wave. She urged members of the public not to rely on the promise of a vaccine and to follow the regulations in place, saying it would make Christmas celebrations more likely. “Everybody has to really get all their resolve together to really pay attention to resisting any urges to break the rules on distancing, on visiting households; to pay attention to keeping indoor spaces ventilated, keeping surfaces and hands disinfected,” Michie said. “Because that will maximise the chance that on 2 December, we’re in a position where we don’t have to continue the lockdown and, better still, be in a position where they can spend Christmas and winter holiday times with loved ones rather than being isolated. “One thing that is quite hopeful, is if you look at the data for Wales, and for Northern Ireland, in both cases really severe restrictions actually have brought the transmissions down. Now whether that will continue is another question.” Michie is not the only expert to call for caution in response to the news that Pfizer and BioNTech’s vaccine candidate is 90% effective in stopping people from falling ill. Speaking at a press conference hosted following the announcement, the deputy chief medical officer for England, Prof Jonathan Van-Tam, urged the public: ”Please don’t relax”, adding, “we don’t know what this means yet for when we can get life back to normal”. Boris Johnson also warned that we “can’t let our enthusiasm run away with us”, urging the public to continue to follow the regulations. A further 27,301 cases of coronavirus were recorded across the UK on Friday. More than 24,000 of those were in England, which is currently under a second national lockdown. Last week, the UK passed 50,000 coronavirus deaths, making it the fifth highest Covid toll in the world.