welcome to bbc news. i'm mike embley. our top stories: coronavirus breakthrough relief as an american pharmaceutical giant reveals a vaccine it says is more than 90% effective. as coronavirus cases in the us exceed 10 million, president—electjoe biden sets up a taskforce and tells americans to wear facemasks. donald trump is still claiming the election was stolen from him and refusing to concede, despite a lack of evidence. now he's sacked his defence secretary. the armenian prime minister has signed a peace treaty to end six weeks of fighting in nagorno—karabakh. he called the agreement ‘painful‘.

leading scientists are cautiously welcoming news of a new vaccine against coronavirus that's proved more than 90% effective in early results. the vaccine, developed by pharma giant pfizer and its partner biontech, has been tested on nearly 44,000 people in six countries, with no safety concerns being raised so far. some experts though point out that the announcement was made on the basis of very early analysis, with the vaccine not yet formally approved. our medical editor fergus walsh reports. this is a huge day for science, and perhaps the world. for the first time, a covid—19 vaccine has been shown to protect against the disease. plenty of caution is needed, but the preliminary results of the pfizer—biontech trial are highly promising. there were more than 43,000 volunteers on the trial, which began in july.

half got the coronavirus vaccine, half a dummy, or placebo jab. interim results showed 94 of the volunteers fell ill with coronavirus — nearly all in the non—vaccinated group. as a result, pfizer says the vaccine is more than 90% effective. it's such a great day for science and humanity. you know, i've never felt, professionally, such a moment ofjoy. and we werejust jumping up and down with joy for humanity, joy for medical advances, to put an end to this dreadful pandemic. the vaccine uses a tiny amount of the genetic sequence of the spike protein which sits on the surface of coronavirus. synthetic material, known as rna, is injected into muscle cells in the arm. this stimulates the creation of antibodies — y—shaped proteins, which should bind onto coronavirus, preventing future infections.

killer t cells are also produced. these should identify and destroy cells which have become infected. scientists around the world have moved at an extraordinary pace to develop coronavirus vaccines. there are 47 in human trials. the uk government has advance orders for six of them, including 40 million doses of the pfizer—biontech vaccine. that's enough to immunise 20 million people, as you need two doses. pfizer says by the end of the year, 50 million doses will be available globally, but only a minority will come here, to the uk. the government's also ordered 100 million doses of the oxford astrazeneca vaccine. we're still awaiting their results. it's thought around four million doses will be available here by the end of the year. at the number ten press briefing, there was a sense of cautious optimism.

of a significant moment in the fight against covid. i have to say that this is really a very important scientific breakthrough. i'm certain of that. but the prime minister said there were several hurdles to clear before the vaccine could be used. and he urged people not to slacken their resolve. we cannot let our enthusiasm tonight run away with us, folks. i'm very sorry to say this. it's more vital than ever now that we follow the basics, that we wait and see whether this vaccine lives up to its promise, we continue with the measures we have in place. and many scientists agree that we can't be sure yet if this vaccine is a game changer. these are very early results. what we really need to wait for is the longer term follow—up of all these participants in the trial to understand how effective this vaccine is say,

four, six months after receiving the dose. pfizer will apply for emergency authorisation for the vaccine. if regulators give approval, the first doses could be used here before christmas. a small first step towards ending the pandemic. fergus walsh, bbc news. akiko iwasaki is a virologist and professor in the department of immunobiology and in the department of molecular, cellular, and developmental biology at yale university. it was difficult to get that right. everybody could do with some good news. is a completely good news or do you have concerns? i was thrilled to hear the number of 90% effectiveness in the vaccinated samples, so we have to be cautious still because the trial is not over, but it is a very great first step. how does

this work? i know there are other teams working on other vaccines with different methodologies, should theyjust give up? is the race over? not at all, we need to have multiple vaccines advancing at the same time. if we rely on one vaccine, we will run out of the typical type of reagents and the types of, for example, the pfizer vaccine requires a very cool temperature for storage and distribution. we need different types of vaccine for different parts of the world. on this particular vaccine, as we world. on this particular vaccine, as we are world. on this particular vaccine, as we are told, it is fragile and unstable, getting it out to enough people and getting two doses out and storing it at the right temperature, all that sounds quite tricky, logistically. right, and that's why i think we need more than one type of vaccine, but if they can solve this issue of storage and transportation at very low

temperature, and can scale up toa temperature, and can scale up to a large number of doses, this is a really promising result for the entire world. this one has been developed with such speed, does that raise question marks with you for possible side effects? it is developed in a very fast speed but we not compromising the for safety, so the only exa m ples we the for safety, so the only examples we have seen so far are the beginning, but as we accumulate more and more examples, of infection and protection from this vaccine, we should find out more about the safety issues. do you have a sense of who will get vaccinated first, and also, as more and more people get vaccinated, how will people know whether they are getting the best one available? for any vaccine to be approved it will be, the safety will be tested and confirmed, as well as efficacy. being at least 50%,

and in this case we might get much better efficacy from the pfizer vaccine. the people who need to receive the vaccine first people like frontline workers, healthcare workers that are treating covid patients, as well as the elderly and the susceptible, high risk individuals. professor, thank you very much indeed. us president—elect joe biden has started asembling his team to prepare for taking over the presidency at the end of january. he spent the day appointing members to his coronavirus taskforce. he said tackling the pandemic was key to rebuilding the us economy. the current occupant of the oval office, president trump, is still refusing to concede victory to mr biden. 0ur north america editor jon sopel reports. donald trump at his rallies repeatedly said that once the election was over, you'd not hear much more about covid. covid, covid! covid, covid, covid, covid! a plane goes down, 500 people

dead, they don't talk about it. it's covid, covid, covid, covid. by the way, on november 4th, you won't hear about it any more. it's true. covid! fat chance. there's a fresh infection outbreak at the white house... because we follow the science... ..with his chief of staff and the person leading the legal fight against the results among those to have gone down with it. 10 million americans have now been infected. and from the president—elect today, a markedly different message. it doesn't matter your party, your point of view. we could save tens of thousands of lives if everyone would just wear a mask for the next few months. not democrat or republican lives, american lives. shares in the us have soared on news from pfizer on the vaccine, an announcement welcomed byjoe biden and donald trump. but how the president must have wished it had come two weeks ago. the president spent the weekend playing golf, and while we know

no more about his future, he today fired his defense secretary mark esper by tweet. well, not fired, he was terminated. donald trump hasn't spoken on camera since thursday, probably a record for this presidency. but his close aides are appearing, and to the question will he concede, this is the answer. that words not even in our vocabulary right now. we're going to go and pursue all of these legal means, all of the recount methods. we're going to continue exposing and investigating all these instances of fraud or abuse and make sure, again, that the american public can have full confidence in these elections. as donald trump vows to explore all legal avenues to continue the fight, some around him are beginning to consider another option. it is that he eventually concedes, but then runs again in 2024. it's happened once before. in the late 19th century, president grover cleveland lost and fought again and won.

with a crane appearing on the skyline today, it's perhaps confirmation that one way or another, donald trump is facing removal from the white house. jon sopel, bbc news, washington. more on that to come. the armenian prime minister says he's signed a painful peace treaty with azerbaijan to end the fighting in nagorno—karabakh. during more than a month of conflict the armenians have steadily lost territory and over the weekend azeri forces took over the regions second largest town, as mark lobel now reports. azerbaijan's territorial gains have been armenian losses during over a month of heavy fighting. devastating casualties on both sides. capturing the disputed region's second—largest town was not just a symbolic victory for azerbaijan, it may have been

the decisive one, forcing armenia's prime minister into a climbdown. in a statement on facebook, he described the declaration is incredibly painful for both himself and his people, but he said it's the best possible ending after analysing the current military situation with experts. he prays that many martyrs who had died defending the fatherland, promising address to the nation in the coming days. there was added pressure on azerbaijan to reach a deal after it shut down this russian military helicopter over armenia. azerbaijan apologised to russia for killing two crewmembers and injuring a third in what they claimed was an accident. as pa rt claimed was an accident. as part of the agreement, russia is now deploying around 2000 peacekeepers to the disputed area. translation: the azerbaijan republic and the republic of armenia will stop at their present position.

russian peacekeeping forces are to be deployed along the contact line in nagorno—karabakh, and the corridor between nagorno—karabakh and the republic of armenia. internally displaced persons and refugees will return to nagorno—karabakh and the bordering areas. turkish peacekeepers are being called in as well to police the disputed area, that found itself once again in original tussle between turkey back azerbaijan, which claims to have reta ke n azerbaijan, which claims to have reta ken land azerbaijan, which claims to have retaken land lost in the 90s, from russian backed armenia, but those gains have come at a price. there is already over one month of bloodshed, costing the lives of thousands of civilians and military personnel. following this deal, armenia's prime minister described it as neither a victory nor defeat, for his nation promising victory in the end, but azerbaijan's resident was insistent that armenia had capitulated. 0ver

insistent that armenia had capitulated. over the past month, there have been several false storms, so this one will be watched closely. stay with us on bbc news, still to come: waiting for the smoke to clear —joe biden is calling for net zero carbon emissions by 2050. could the biden presidency have a real impact on the climate? the bombastic establishment outsider donald trump has defied the pollsters to take the keys to the oval office. i feel great about the election results. i voted for him because i genuinely believe that he cares about the country. it's keeping the candidate's name always in the public eye that counts. success or failure depends not only on public display, but on the local campaign headquarters and the heavy routine work of their women volunteers. berliners from both east and west linked hands and danced around their liberated territory.

and with nobody to stop them, it wasn't long before the first attempts were made to destroy the structure itself. yasser arafat, who dominated the palestinian cause for so long, has died. the palestinian authority has declared a state of mourning. after 17 years of discussion, the result was greeted with an outburst ofjoy when the ministers who'd long felt only begrudgingly accepted among the ranks of clergy suddenly felt welcome. this is bbc news. the latest headlines: the first effective coronavirus vaccine has been developed, initial tests suggest it is capable of preventing more than 90% of people from getting covid—19, according to preliminary findings. but experts warn of logistical challenges ahead. the armenian prime minister says he's signed a deal with the leaders of azerbaijan

and russia to end the conflict in nagorno—karabakh. he described the deal as "inexpressibly painful". more now on the news that president trump has dismissed his defence secretary, mark esper. mr trump's announcement, on twitter, gave no reasons. during the summer, the two clashed over the president's suggestion that the military could be used to end the widespread protests against racial discrimination and injustice, although mark esper himself referred to american cities as "battlespaces" and said protesters needed "dominating". he's now been replaced by christopher miller who currently serves as director of the national counterterrorism centre. professorjosh kastenberg, is a professor at the university of new mexico law school. before that he had a 20—year career as a lawyer and judge in the us air force. very glad to talk to you. what you make of this, first of all? first of all, there have only been two acting defence retirees in the 71 years since the department of defence was

founded. this is highly unusual, and in particular because pat sha na han unusual, and in particular because pat shanahan was ready in the department of defence, as was william howard taft, the fourth under george hw bush. what is different now as there isa what is different now as there is a government shutdown looming on december 11, in the midst of a contested election, and the fact that president trump has nominated an acting defence secretary, which has a question in my mind, and in the minds of many legal scholars in this area, as to whether the acting secretary, christopher miller, will possess the authority to commit what is to the united states military, because it appears contrary to law and executive order. and in policy terms, what do you read into it? it seems in some ways mr aspro and into it? it seems in some ways mraspro and mrtrump into it? it seems in some ways mr aspro and mr trump were not that far apart. if christopher miller does manage to do the job, how do you expect him to do it? it is hard to do without

senate confirmation with 70 days to go in a presidential administration. there is a question looming as to why this occurred. did it occur because president trump was unhappy with mark esper and decided to fire him before he would resign? 0r fire him before he would resign? or is this being done for another purpose? and that may be to remind the nation, the courts, state governors, state legislatures, and potential electors, that president trump remains the commander—in—chief, and with all the legal battles going on in us courts right now, with some arguments that faithless electors are perfectly constitutional, there is a bit of worry going on in the united states right now as to whether this movie is more than unhappiness, and has a nefarious component to it. but under the law, under the constitution, the president has the authority to dismiss

cabinet secretaries, and so while there has been a violation at this point, there isa violation at this point, there is a question as to whether christopher miller would naturally have the ability or the authority to order the united states military to do anything, because it seems to go against executive order 13-50, 533, dated go against executive order 13—50, 533, dated march one, 2010. it makes the deputy, david norquist, the actual person who should assume the position and seal the senate confirms christopher miller. professor, it sounds like we will be coming back to this. thank you very much indeed. thank you very much indeed. thank you. president—elect biden has made the fight against climate change one of his top four priorities, calling for net zero carbon emissions by 2050. 0ur science editor david shukman looks at the possible impact that a biden presidency could have on global efforts to tackle climate change. the battle to save our planet by getting climate under

control. joe biden believes the changing climate is an urgent threat, unlike donald trump, who withdrew from the only international agreement to tackle it. the united states will withdraw from the paris climate accord. applause now there'll be a huge push for renewable energy — on an epic scale, says mr biden, for the us to be carbon neutral by 2050. a difficult challenge, but climate experts say it's needed. biden understands time is short and intends to act vigorously and with the greatest ambition of any us president ever, internationally, where he has huge authority. and that means huge incentives for other countries to reduce their emissions even as he tries to regulate us emissions ourselves. oh, my god. fires, droughts and all kinds

of extreme weather are set to intensify as global temperatures rise. so mr biden promises action on his very first day in office. he's pledged to rejoin the paris agreement. negotiated five years ago, amid great celebrations, it was then abandoned by mrtrump. the agreement is about cutting the gases that are heating up the atmosphere, and many hope that it will make all the difference to have america, the world's largest economy, taking part once again. unless we all address climate change, we will all be vulnerable to climate change, so it is very refreshing to know that we are going back into a collaborative frame of mind that helps everyone. but coal mining and many heavy industries are at stake. joe biden is offering green jobs instead, but he's bound to face opposition in the senate and maybe

the courts as well. this comes as more than 100 countries are now talking of going carbon—neutral around the middle of the century, and america's new leader will be working to make that happen. david shukman, bbc news. a quick roundup of some of the other menus. 50 people at least have died in honduras since storm eta hit last week. it left a trail of destruction through central america since it first made landfall in nicaragua on tuesday. i hundred and 50 people or so —— around 150 people went missing in landslides.

the bbc has promised to launch an independent investigation into claims made by earl spencer, brother of the late diana, princess of wales, that he was deceived by the reporter martin bashir, ahead of the princess's explosive television interview in 1995. earl spencer says the former panorama reporter had used false bank statements as part of his attempts to encourage the princess to grant him an interview. the bbc‘s director—general says the corporation is taking the matter very seriously. 0ur correspondent jonny dymond reports. it was one of the biggest tv interviews of all time. princess diana laying bare her loveless marriage, her love for another man, her suffering. you always think you're prepared for anything, and you think you have the knowledge of what's coming ahead... butjust how did martin bashir get the interview? diana's brother, charles spencer, says martin bashir showed him forged bank statements suggesting that one of his staff was selling secrets. it was a tumultuous

time for diana. she thought she was being spied on, that her life might be in danger, that she was being briefed against by prince cha rles' staff. well, my husband's side were very busy. martin bashir‘s forged bank statements looked like evidence of dirty tricks. it was, her brother says, an attempt to win access to diana. and matt wiessler, the graphic artist that created those bank statements, has now spoken out. i got home from work and i got a phone call from martin bashir, and he wanted me to do a favour for him and it was really urgent and really important. martin asked me to make up a couple of bank statements that he needed the following day, and he did say that they were just going to be used as copies. so, on that night, i was just making some props for filming purposes.

charles spencer says he's speaking out now, 25 years later, because he found out recently that the bbc knew about the forged bank statements. the bbc did hold an inquiry in 1996 when the bank statements were first made public. never published, it cleared martin bashir of wrongdoing. the men and women who ran bbc news in the ‘90s have all moved on. the new director—general has acknowledged the deceit and promised an independent inquiry. there are a lot of questions. but so far, no answers from martin bashir — now the bbc‘s religion editor. seen up and about this weekend, the bbc says he is recovering from heart surgery and is unable to answer questions. jonny dymond, bbc news.

much more on all the news for you any time on our website and on our twitter feeds. thank you for watching. hello there, we've got a bit more murky weather to come over the next few hours. now, this weather watcher picture, i quite like it. this is the fourth rail bridge of course or at least half of it. the other half is subsumed beneath low cloud, the fog and the murk. futher southwards meanwhile, we've got these bands of rain crossing england and wales moving at a northeastward direction thanks to an area of low pressure. this weak low pressure is also drifting northeastwards. but some of this rain is actually washing the fog out of the atmosphere. so, it's not quite as murky as it has been. still some mist, still some low cloud. the really dense fog is away from that rain

across northeast england, particularly eastern scotland and some patches through the central belt. and where it is worse, the fog, visibility down to 100 metres so it is really quite dense. tricky travel conditions are to be expected if you're out and about over the next few hours. a mild night though and a mild start to tuesday. this little low pressure will continue to push its way northeastwards with a few more bursts of rain during the morning, a lot of cloud and remember the murky weather too for east scotland, northeast england. that mist and fog taking awhile to lift into low cloud. through the day though, i'm optimistic that we'll see an improvement in the weather. a little bit more in the way of sunshine breaking through the cloud. there will still be a few showers dotted around, mind you, into the afternoon but it's another mild one. temperatures 13—15 celsius. there'll be some further change in the weather midweek though. another area of low pressure is going to move in. this one is much more potent.

this band of rain will get all of us, and the rain will become really quite heavy and squally. so, sudden heavy downpours and as well as that, it's going to be very windy as well with the strongest winds just rolling in on and ahead of the front. also becoming quite windyjust behind the front as it works and across the south coast of england. now, the wind gusts could be stronger to bring down a few tree branches. so, we could see some localised disruption. and this band of squally rain with strong gusty winds will continue to push eastwards as we go on through wednesday night. now, as that band of rain clears eastwards, we'll see something of an improvement in the weather to take us into thursday as this ridge of high pressure builds in behind us. that means that we'll have some descending air. that will break the cloud up nicely and will see the weather brighten up with some decent spells of sunshine. thursday probably the sunniest day of the week but then further changes on friday. more rain is on the way.

this is bbc news. the headlines: the first effective coronavirus vaccine has been developed — preliminary findings suggest it's capable of preventing more than 90% of people from getting covid—19. the developers, pfizer and biontech, describe it as a "great day for science and humanity". experts are warning of some logistical challenges ahead. as coronavirus cases in the us pass 10 million, president—electjoe biden has set up a taskforce of specialists who have worked with both democratic and republican administrations. he has warned of the effects of a second wave and called on all americans to wear facemasks and follow other safety guidelines. the armenian prime minister says he's signed a deal with the leaders of azerbaijan and russia to end the conflict in nagorno—karabakh. nikol pashinyan promised to disclose details in the coming days, but described the deal as ‘inexpressibly painful‘. russian peacekeepers are expected to be deployed