animals into humans, there were warning signs. >> every few years there's a new spillover event with a new disease that humans have no immunity to. >> it's a likely probability that this one originated from animals naturally as well. but the possibility also remains that the virus leaked from a lab. >> the wuhan novel respiratory coronavirus lab. the disease is the same name as the lab. >> it's a laboratory at the heart of the city, where the outbreak occurred, that's undertaking some risky work. laboratory accidents happen much more often than we know. >> the biological window to learn what happened, that window might be closing. good evening. i'm dr. sanjay gupta. it's been nearly two years since the world first learned of covid-19. and there are still no definitive answers of it origins. no clear culprit. no smoking gun. all we can say based on the evidence we have now is that it wasn't intentionally bioengineered. so over the last several months, we've been speaking to the world's top scientists. it wasn't easy. almost all of them faced death threats because of their work on this topic. some of them have never spoken on camera before. but with their help, tonight we try to push past the politics and take a look at the scientific evidence for the two leading theories. the zoonotic hypothesis that the virus spilled over into humans from a bat or another intermediary animal. as has been the case with coronavirus outbreaks like sars in 2003 or mers in 2012. versus the lab leak hypothesis, the idea that the virus leaked accidentally from a lab. we start by taking a deeper look at the only scientific study of the virus's origins to date. in january 2021, the world health organization launched this group of scientists and doctors to wuhan. >> they were swarmed with photographers, local and foreign media, tracking their every move. >> the team's mission, to better understand the origins of the virus. >> most of the attention has been put on the seafood market. >> chinese authorities traced a new deadly virus back to this seafood market in the city of wuhan. >> those earliest months in wuhan were filled with lots of confusion and obstruction from the chinese government on just how contagious, deadly, and dangerous this virus really was. >> the original reports coming out of china were that it was not highly transmissible, which was suspicious. >> from the pandemic's earliest days, the chinese government refused offers of help from the u.s. centers for disease control and prevention, global public health workers, and academic researchers. simply put, nobody was allowed in. >> we wrote to our contacts in china and said, can we help. our goal is to have veterinarians and field teams in there right at the beginning of the first case, to say can we trace back the origins right there and get the evidence while it's fresh, before it's all removed and cleaned up. and unfortunately the crisis was too intense. >> the doctor is a renowned virus hunter and president of the virus alliance. he and his team try to determine which pathogens pose the greatest risk to human health. >> there are viruses in mammals, wildlife, around the world that could become emerging diseases and pandemics in people. >> the united states submitted three u.s. researchers for selection. all three of them were rejected by china, which did ultimately have final say, since the w.h.o. was coming into their country. the only american who was permitted on the team was peter dazak who we know to be the organizer of "the lancet"'s statement and the wiv. >> the wiv is wuhan institute of virology. dazak would later draw fire for his work with one of the lab's researchers. we'll get back to her inform in february of 2020 in the earliest days of the pandemic, dazak was the drivings for behind an influential letter. >> it's almost impossible to overstate the importance of this open letter in "the lancet." >> he and 26 other prominent scientists wrote, quote, we stand together to strongly condemn conspiracy theories suggesting that covid-19 does not have a natural origin. >> it almost immediately succeeded in characterizing the hunt for the lab leak theory as not just unscientific but even xenophobic. it really kind of sets the political tone. >> it casts any my hypothesis on the virus's origins as a c conspiracy theory. >> dazak discusses signing the "lancet" letter in an email to other scientists. writing, quote, we'll maximize an independent voice. >> people may say, look, you're too close to it. you work in china. you are part of this alliance that helps fund some of the research that's happening there. maybe there's a conflict. >> well, how can there be a reflect when it's a statement of support? >> the thing i think that struck me, it was so early. how were you so certain at that point to go ahead and label anything that was not a natural origin a conspiracy theory? >> well, because the theory at the time was that this is a bioengineered virus. >> so this was not in any way to take off the possibility that this could have still leaked from a lab even if it not been bioengineered? >> that wasn't what was being said at the time. what was being said at the time was this was a bioengineered virus that had been released by chinese scientists. >> there were concerns, is there something here that might be the signature of human manipulation? >> initially in january, knowing the type of work that was going on at the wuhan institute of virology, we started thinking things like, look, we need to consider the possibility that this is maybe not a natural virus. >> dr. christian anderson is an evolutionary biologist at the scripps research institute. in late january 2020, he wrote to dr. fauci in correspondence that was also later released. >> we are concerned about this particular virus. we think that what we are looking at here might be different than what we would expect to see just from a naturally-emerged virus. >> anderson and other scientists worked around the clock, searching for clues deep in the genome. >> the engineering aspect of this very quickly we realized we just don't have the evidence to support that. >> even though they initially thought this novel virus had evidence of bioengineering, they subsequently found evidence of similar traits in other known naturally occurring viruses. >> we debated up one side and down the other and ultimately decided, if you were a human trying to design a really dangerous coronavirus, you would not design this one. >> if we can find any evidence of this virus previously having been sequenced or worked on, maybe there's fragments of the virus which were used previously in experiments, it would be, quote unquote, a smoking gun. and we didn't find anything at all. >> and by march 2020, anderson published what would become the most influential paper in support of the natural origin theory. by the end of april 2020, the bioengineered weapon theory seemed to have been laid to rest. >> the director of national intelligence puts out this really remarkable memo in which they agreed with the broad scientific consensus that the virus was not man made or genetically altered. a few hours later, president trump comes out. >> and what gives you a high degree of confidence that this originated from the wuhan institute of virology? >> i can't tell you that. i'm not allowed to tell you that. >> over the course of 2020, however, more and more revelations emerged related to the wuhan institute of virology. >> at least three staff members were sickened early on. they were so sick, they had to go to the hospital. here in china there's not unusual given that there's no primary care system. still, to be hospitalized with an unknown respiratory illness, suggests this virus was spreading even in november in 2019 in wuhan. >> wuhan scientists deny this ever happened. but then reports of a massive pathogen database containing thousands of bat coronavirus entries just went offline. >> just a few months before the world becomes aware that there is this dangerous virus circulating in wuhan, the wiv removes from the internet this catalogue of 22,000 viral samples that it had been working on, that it had been studying. >> what happened to the bat coronavirus database in september of 2019? >> they told us they were revising it, making it more searchable, and that they were then getting hacked over and over again, so they didn't put it back up. that's what they told us. >> do you believe that? >> well, it's not my role to believe or not believe. i'm a scientist. i look at data and information, and we look at it objectively. >> you're a scientist, but i'm saying, you do have to look at history as well. and there's been concerns that there's been a lack of transparency. >> right. when i looked in that database, it was simply a list of samples with sequences attached, most of which had been published, probably the vast majority right now. so we knew what was in those databases. >> if the data was out there, why were they so concerned about it getting hacked? >> i don't know. more importantly, people who think the database has the answers to sars-cov-2, i recall doubt that. >> so help me god. congratulations, mr. president. >> in early 2021 as one presidency ended and another began, dr. robert redfield, former head of the cdc under the trump administration and a career virologist, told me this. >> i still think the most likely etiology of this pathogen in wuhan was from a laboratory, you know, escaped. >> you're now saying that when you piece it together, you think the virus probably originated in a lab? >> it's very possible that someone acquired that virus, got infected. and i don't think i've heard another argument that makes sense. it's interesting, you know, the w.h.o. mission right now, and what they're coming out, i'm anxious to read their report. coming up, that world health organization report on covid's origins. and the controversy that quickly followed. we're carvana, the company who invented car vending machines and buying a car 100% online. now we've created a brand-new way for you to sell your car. whether it's a year old or a few years old. we wanna buy your car. so go to carvana and enter your license plate answer a few questions. and our techno wizardry calculates your car's value and gives you a real offer in seconds. when you're ready, we'll come to you, pay you on the spot and pick up your car, that's it. so ditch the old way of selling your car, and say hello to the new way at carvana. today let's paint with new behr dynasty™... so that you can be proud of your walls. go ahead, throw your wine on it. what? it's also scuff resistant. you're paying for that! introducing behr dynasty™, the best of behr. exclusively at the home depot. after a year of wrangling and delays, the w.h.o. is set to finally publish their first report into one of the most important questions into this novel coronavirus. why did it start chemical. >> this comes as the former cdc director dr. robert redfield tells our sanjay gupta that he thinks the coronavirus originated in a lab in wuhan. >> that's not implying any intentionality. i do not believe this somehow came from a bat to a human and at that moment in time, the virus that came to the human became one of the most infectious viruses that we know in humanity. >> dr. redfield's comments boosted the lab leak theory and so did a u.s. intelligence report stating that there were sick researchers at the wuhan institute of virology in november of 2019. >> the u.s. intelligence community released a memo saying that several lab workers got sick with covid-like symptoms in the autumn of 2019. >> did you investigate that possibility? >> i remember specifically asking the wuhan lab director and the staff about people who got sick. and we repeated that and pushed and asked pretty tough questions around that. and they refuted it. >> according to the wuhan institute of virology's own practices, they would have taken blood samples around that time. >> yes. >> did you get to see those blood samples? >> no. no. but we did ask them. we asked them if they would do that. they confirmed they did take samples, that they tested them after the outbreak and that they were negative for covid. >> on march 30, 2021, more than 15 months now after the pandemic began, the world health organization released its highly anticipated report on the origins of covid. the w.h.o. team's conclusions? a direct spillover from animals to humans was a possible to like way pathway. a jump from an intermediate host was likely to very likely. the virus coming in through frozen food was a possible pathway. and a laboratory incident was deemed extremely unlikely. swiftly, criticism of the report came from far and wide. >> more than a dozen countries issued a joint statement raising concerns about the credibility of the research and the independence of the findings. >> it lacks crucial data, information. it lacks access. it lacks transparency. >> the report dismissed the possibility that the virus was the result of a lab accident. but the organization's own chief questioned that, saying the theory needs further investigation because, quote, i do not believe that this assessment was extensive enough. >> dr. tedros said the dismissing of the lab theory was premature. he's the director of the w.h.o. to have that criticism from one of his own studies, that really caught my attention. >> that's his prerogative. that's the director general of w.h.o. we're the people on the ground who write the report and submit it for him to look at and for the public to see. we did our job and now he's doing his job. >> critics say that job was seriously flawed from the outset. >> was it an investigation? >> its official title was joint study, which is very important, because if it's a joint study, it's a collaborative study between the w.h.o. and the member state, china. the public looked at this as an investigation from the start. and i think that was a mistake. and i think w.h.o. should probably have spoken out more forcefully and said, we are not going to do a forensic investigation of the lab. >> why not? >> well, because it's -- umm, a member state organization, w.h.o. so china is part of that. and it's a joint decision among the member states as to what happens on that study. >> for a lot of people who are sort of looking from the outside in, they say there's all these different possibilities, why weren't they explored or investigated thoroughly, including a forensic examination of the lab. is that a fair line of questioning? >> absolutely, of course. we all have to agree on what happens for it to happen. >> both foreign and chinese scientists were part of the w.h.o. effort. and team members said they had to unanimously agree on the contents of the report. the head of the team, w.h.o. food safety specialist peter benembarak, told tv 2 their chinese counterparts didn't want to include the lab leak theory at all. [ speaking foreign language ] >> was a full evaluation of the lab meant to be part of this report? >> we didn't have people on the mission team who were experts in biosafety, biosecurity. so it wasn't really their mandate to do. >> if the report was never meant to investigate the lab leak theory, why was dr. tedros critical of it? >> they classified it as extremely unlikely. for us to be able to take it off the table, it needs to be studied properly, it needs to be studied thoroughly. >> it was just one of many red flags that dogged the report. >> they had very, very limited access to the labs. they were very limited in their movements. >> members of that w.h.o. team began to criticize some of the lack of data they received. they questioned the transportation from their chinese counterparts. >> at the seafood market, traces of covid-19 were found on the floors, walls, and surfaces. the w.h.o. team was told that no live animals were being sold prior to the outbreak. that was despite images like these. >> cnn has obtained this video filmed inside the market, images of the market from early december, taken by a concerned customer indicate it was apparently selling other live wild animals. >> we now know that animals were in fact sold there, live animals, which is something that china has denied. but it's clear that annals like raccoon dogs that are susceptible to these viruses and likely intermediate hosts were sold there. >> do you think it was an adequate investigation? >> i just think they were not fair and objective. they had looked reasonably hard at one plausible hypothesis, but really had ignored or brushed aside the other, the laboratory-associated hypothesis. >> how much of the report was given to zoonosis? >> the total was about four pages out of 313. and in those four pages, the title of the section was "conspiracy theories." >> there's a lot of smoke here. no definitive flame. but, database goes down, no sharing of samples of these potential lab workers who got sickened, no forensic analysis of the lab, it starts to sound like there wasn't a really definitive investigation of the lab leak theory. >> i think that's right, there's not been a definitive investigation of the lab leak theory. >> will there be? >> i think it needs to follow the evidence. if there is definitive evidence of a lab leak, that needs to be known. there's none yet. >> part of the reason there's none is because information isn't shared. >> right. if we want to see information shared from chinese on what went on in the lab, we need phase 2 to begin very rapidly. >> the chinese government has rejected a phase 2 of the world health organization study. and now even says the world should look to other countries for the origins of covid-19. coming up, the scientist known as the bat woman. >> she also worried, is there a chance it could have come from our lab. and just being sustainable isn't enough. our future depends on regeneration. that's why we're working to not only protect our planet, but restore, renew, and replenish it. so we can all live better tomorrow. ♪ (burke) i've seen this movie before. (woman) you have? (burke) sure, this is the part where all is lost and the hero searches for hope. then, a mysterious figure reminds her that she has the farmers home policy perk, guaranteed replacement cost. and that her home will be rebuilt, regardless of her limits or if the cost of materials has gone up. (woman) that's really something. (burke) get a whole lot of something with farmers policy perks. wait, i didn't ruin the ending, did i? (woman) yeah, y-you did. ♪ we are farmers. bum-pa-dum, bum-bum-bum-bum ♪ we're fast approaching the two-year mark of this pandemic and we don't know how it started. >> this is a coronavirus, so it's likely that it came from a bat. >> the question is why. i mean, was it because in that wet market they were selling fried bats, it entered the human population by people eating fried bats or drinking bat soup, or was there a laboratory working with coronavirus that a lab worker or workers got sick and that's how it entered the human population ? >> are bats just carrying a lot of these types of viruses that aren't making them sick but could potentially spill over to other animals including humans? >> bats carry a lot of different viruses. they're good at supporting a lot of viruses in the body without getting harmed. >> when a mysterious disease was circulating in wuhan at the end of 2019, dr. lee was one of the first people to be alerted. >> dr. lee is known in china as the bat woman. >> on december 30 she got a call from her boss, the director of the whole institute, who said drop whatever you're doing and get back to the lab right now. >> after all, she is the director of the center for emerging and infectious diseases at the wuhan institute of virology. >> she's given some of the greatest insights into coronaviruses. she figured out where sars came from. >> 2002 and 2003. that's when the first sars outbreak swept across asia. the original sars infected about 8,000 people around the world and led to nearly 800 deaths. that's a 10% fatality rate. but luckily, it wasn't very contagious, and it was spread only by people showing symptoms. within months, researchers had traced that virus back to live animals being sold as food at wet markets in southern china. >> the chinese government today began slaughtering the animal believed to spread the disease. about 10,000 cats will be destroyed. >> but how had it gotten into civet cats? where did the first sars actually originate? well, virus hunters like dr. lee and researchers from ecohealth alliance set out to test a theory that sars i had come from bats. >> they sampled case of from all over southern china. in some cases they had to crawl on their bellies to get in through the tight crevices into the caverns were bats are. they collected lots of bat samples, then took all these samples back to the lab. >> it would take almost a decade. remember that, nearly ten years, to figure this out. but dr. lee's work confirmed that sars i had in fact started in bats. now, by the time covid was first detected in 2019, the wuhan institute of virology was home to the largest collection of bat coronavirus samples in the world. >> she also worried because her lab's in wuhan. is there a chance it could have come from our lab? >> within days, her team had isolated the virus, sequenced it, then shared its full genome. >> as soon as they had the sequence, they were able to determine it had never been in her lab, had nothing to do with the viruses she had studied before. >> does the data exist to say convincingly there weren't early ancestors of the virus in the lab? >> dr. lee herself has been asked about this and she has denied it. they've tested all their bat samples in the freezers, and none of them had sars-cov-2. i trust them. we've been talking about some of the best scientists in the world here. >> but another important origin theory stems from dr. lee's lab in wuhan. somebody's the closest relative to sars-cov-2 was this bat virus called ratg-13. >> ratg-13 was found in a horseshoe bat. the sample was taken by a team of researchers from the wuhan institute of virology. it was collected from a mine were six miners had worked and were later hospitalized with sars-like symptoms back in 2012. three of them died. >> that is the closest known relative of sars-cov-2. and we don't even know that that's the virus that made those six miners sick. >> how close are we talking about here? >> 96% similar. sounds like a high number. but in terms of virus evolution, that 4% difference takes decades. their last common ancestor probably was out there in nature 30 or 40 years ago. >> she said there's a zero chance this came from her lab. what did you think of that? >> so i would like to see what made her think there was a zero chance that it came from her lab. can you show me the data that substantiates your hypothesis or your claim? >> dr. elena chan, postdoctoral fellow at harvard, has consistently challenged the widely accepted zoonotic theory, often going up against well-established vierrologists d in science journals. she published a letter in "science" magazine in may of this year calling for an investigation of all possible origins. what would you like to see specifically? >> i would like to see access to the database that's gone missing. >> the same missing pathogen database that was taken offline by wiv in september of 2019. >> this is a database that the mission was to collect all the viruses in the world and use it to help prevent pandemics. so this is a pandemic. so why didn't they share that database with other scientists so they could figure out how dangerous this virus is, where did it come from? >> what is the status that have database now? have you been able, as an of me this w.h.o. team or in any capacity, to look at that data? >> no. >> that sounds concerning, peter. if it is serious, and we're trying to be as thorough as possible, maybe it amounts to nothing, but i think the fact that you still haven't seen that database, it's just got to raise a lot of eyebrows as we go forward. >> rightly so. i think china should be more open about the things that they've not released. but this is where politics comes into it. when a country is under attack, they defend. and scientists are caught in the middle of it. it's really unfortunate. >> dr. lee and others at the wuhan institute of virology did not respond to interview requests for this documentary. coming up, lab safety concerns in wuhan. >> the experiments that they did under the conditions that they did them were risky. there's software. and then there's industrial grade software, forged from decades of industrial experience and insights. meet honeywell forge. analytical software that connects assets and people to deliver a cybersecure record of your entire operation. so that everyone, in your boardroom and beyond, speaks the same language. honeywell forge. industrial grade software. ♪ i see trees of green ♪ ♪ red roses too ♪ ♪ i see them bloom for me and you ♪ (music) ♪ so i think to myself ♪ ♪ oh what a wonderful world ♪ why do you think there's such a renewed interest in the lab leak theory? >> there are some scientists speaking up that we can't rule out the possibility of a lab leak. >> dr. ralph barak is one of them. he's also one of the world's top bat coronavirus researchers. his lab developed some of the most effective treatments for covid-19. and he has collaborated in the past with dr. shi zhengli of the wuhan institute of virology. over the course of 2021, barack has grown increasingly concerned about lab safety at the wiv. >> their papers indicate they did much of their work with these bat viruses under biology safety 2 conditions. >> there are four tiers of biosafety. bsl 1 is the lowest. and bsl 2, pathogens with known vaccines or cures like measles can be worked on. lab coats and gloves are worn and all work is performed under a biological safety cabinet hood. eye protection and face shields are optional. some critics have likened bsl 2 conditions to a dental office. >> there are many more laboratory accidents or laboratory acquired infections in bsl 2 as compared to bsl 3. >> while there is no international standard for coronaviruses, dr. barak sees bsl 2 is too risky. >> we do all our work under bsl 3 conditions. we wear portable breathing apparatuses with tieback suits so workers are protected from anything that might be in the laboratory. >> now the wuhan institute virology is best known for its world class bsl 4 lab which became fully operational in 2018. those labs handle the world's most dangerous microbes with no known cures or treatments. >> this laboratory will mainly be used for research on highly pathogenic infectious diseases for which there are currently no medicine or vaccines. >> but in the year that it opened, u.s. diplomats visited the lab and expressed their concerns. >> they told their washington colleagues if a lab accident happened at this lab it could cause an outbreak of a bat coronavirus pandemic. >> that same year, wuhan scientists authored a paper on biosafety labs across china, warning in part that there was a lack of enough operable technical standards. several labs in wuhan handled bat coronaviruses. >> this is wuhan center for disease control. this is one of the labs within wuhan. >> inside, lower level biosafety labs that likewise evolved with the study of bats and coronaviruses. >> all the procedures that i saw happening over there would be the same as if in any other country that i've worked in. >> dr. danielle anderson is the last and only foreign scientist who trained and worked in the wuhan institute of virology's bsl 4 labs. when she left wuhan in november of 2019, she had no inkling of the pandemic to come, no word of an illness spreading in wuhan, no rumors of sickened workers. in fact she was planning to return in early 2020. >> you need to know the symptoms of that particular pathogen that you work with. and if you experience any of those symptoms, they need to be reported. >> she spoke to us from australia where she now works at the doherty institute in melbourne. >> with bsl 4 in particular, every day we have to take our temperature and our blood pressure. and it's recorded in a logbook. also at wiv, which is not go that's done everywhere, before i ever stepped foot in the lab i went to the hospital, had a blood sample taken, and that was stored. >> dr. anderson worked on ebola and nipa virus in wiv's bsl 4 labs and she attests to the high standards at that specific level. but again, it's not the bsl 4 that concerns dr. barak. it's coronavirus being worked on at lower biosafety level conditions like bsl 2. >> the experiments that they did under the conditions that they did them were risky. >> the wuhan institute of virology did not respond to interview requests for this documentary. coming up. >> you're saying that's not gain of function? >> that is correct. and senator paul, you do not know what you are talking about. >> is this sort of gain of function research, was it happening at the wuhan institute of virology? dr. fauci, knowing it is a crime to lie to congress, do you wish to retract your statement of may 11 where you claimed that the nih never funded gain of function research in wuhan? >> senator paul, i have never lied before the congress. this paper that you are referring to was judged by qualified staff up and down the chain as not being gain of function. >> these exchanges seem to assert that u.s. taxpayer dollars via the nih, through your organization, went to the wuhan institute of virology and funded gain of function research which may, not definitively by any means, but may have been a source of this pandemic. what do you say? >> that's just plain not true. dr. fauci testified publicly, under oath, that that's not true. and he's right. we didn't do work that ran against any of the rules. >> and dr. francis collins helped to define those rules. >> let's be clear. there is no evidence that anything we funded did anything wrong. >> he's the longtime director of the national institutes of health. she's also dr. fauci's boss. >> there is no evidence that any gain of function research as we define it in the united states or as we have supported it played any role in this outbreak of covid-19. >> gain of function research. it's a complicated and controversial topic that first rocked the scientific community a decade ago. >> researchers in wisconsin and the netherlands working separately have created a form of the deadly bird influence virus that can easily spread from person to person. >> the nih funded a dutch scientist who did something really wild. he engineered the avian influence virus to make it more deadly to mammals by making it air airborne. >> when a virologist revealed details of his work on the h1n1 and infected ferrets. >> they create a virus like h5n1 and trained it to be efficiently transmissible to other animals, that's scary. >> that bird flu work which was partially funded by the nih sparked a debate that led to a 2014 moratorium by the obama administration. that pause was lifted in 2017. under new rules gain of function research was given a very specific definition. >> gain of function research works with a potential pandemic pathogen in a way for humans that could enhance its virulence or its transmissibility. >> is this sort of gain of function research, was it happening in wuhan? >> they're working on bats sars like viruses that have never been shown to cause human infection. >> he told "the new york times" my lab has never conducted the gain of function experiments. >> if the wuhan institute was somehow trying to manipulate a virus that occurred in nature to make it even more dangerous. >> the research predicts pandemics in the future. it wasn't to make viruses more dangerous. >> but maybe we're getting too hung up on the strict definition here. at the core of this debate is the question, do the benefits of this type of research outweigh any possible unforeseen or unusual risk? >> how close are you getting towards the very thing that we most fear? the highly transmissible, highly virulent virus like sars cov2, the virus that caused this pandemic. where you take the spike protein another virus could that type of research be done in wuhan and potentially lead to a new pathogen? >> not sars cov2. >> the sequences were a million miles away from sars cov2. the spike proteins, there is no way that was anywhere in the same universe as what emerged as sars cov2. all is lost and the hero searches for hope. then, a mysterious figure reminds her that she has the farmers home policy perk, guaranteed replacement cost. and that her home will be rebuilt, regardless of her limits or if the cost of materials has gone up. (woman) that's really something. (burke) get a whole lot of something with farmers policy perks. wait, i didn't ruin the ending, did i? (woman) yeah, y-you did. ♪ we are farmers. bum-pa-dum, bum-bum-bum-bum ♪ in business, it's never just another day. it's the big sale, or the big presentation. the day where everything goes right. or the one where nothing does. with comcast business you get the network that can deliver gig speeds to the most businesses and advanced cybersecurity to protect every device on it— all backed by a dedicated team, 24/7. every day in business is a big day. we'll keep you ready for what's next. comcast business powering possibilities. opreza: trabajar en recology es más que un empleo para mí, es una tradición familiar. tomé la ruta de mi padre cuando se retiró despues de 47 años. ahora le muestro a la nueva generación lo que es recology como una compañia que pertenece a los empleados. estamos orgullosos de haber creado el sistema de reciclaje. convirtiendo a san francisco, en la ciudad mas verde de america... sigamos haciendo la diferencia juntos. the u.s. intelligence community is back with its report on the origins of covid-19. the results are inconclusive. >> the chinese said they closed the door to any phase two of the w.h.o. investigation. >> beijing has accused the u.s. of politicizing the pandemic, vehemently denying the possibility of a wuhan lab leak. >> the u.s. should invite w.h.o. experts to investigate fort dietrich. >> chinese officials call for the world health organization to investigate a lab leak at the u.s. army medical research institute in maryland. backed by an aggressive social media campaign directed from beijing. to be clear, there is zero evidence to support that notion. >> the politics of this have taken a life of its own. we need to make it back to the science. >> one of the things that keeps coming back to, you want science, evidence, data, the database of bat coronaviruses was taken down and blood samples from workers at the lab, they don't have access to those. they can't do a forensics examination of the lab. but if they don't give the most basic data, how is it science driven? >> we need to work with the country. we can't extract something we don't have access to. this is true for china and sars cov2 and the next one as well. >> the next pandemic. according to every scientist we spoke to it's not a question of if, it's a question of when. and the w.h.o. says the newly formed scientific advisory group for the origins of novel pathogens may help them prepare for what is to come. >> the main purpose of the sago is to establish this overarching framework for future pathogens but for sars cov2, the first order of business for them is to evaluate where do we stand. >> if the lynchpin is whether or not china agrees, how does it work? >> we need collaboration to go into a country. we don't have a choice. so let's build something stronger for the future. ♪ >> without a doubt the hunt for covid's origins is a daunting task, it's like trying to find a needle in a haystack. but when it comes to a pandemic, the haystack is planet earth. discovering answers requires identifying and uncovering microscopic scientific clues. while we may never have a definitive answer, we keep searching in the hope we can be better prepared for future pandemics. thanks for watching. good night. good evening. tonight, award winning documentary filmmaker ken burns is here to showcase his work on the life and turbulent times of muhammad ali. but we will also be talking about this troubled moment, which he called equal in magnitude to the second world war, great depression, and the civil war. having made widely acclaimed films on all three, ken burns' assessment about the state of democracy right now. we think is certainly worth listening to. so is historian and "washington post" contributing columnist, robert kagan's, take. he writes today, the united states is heading into its greatest political and constitutional crisis since the civil war with the reasonable chance over the next three to four years of incidents of mass violence, the breakdown of federal authority, and division of the country into warring red and blue enclaves. this is not some wild-eyed radical, by the way. nor is former cia director michael hayden, who warned only a thin veneer of civilization protects any democracy. even our own. nor are reporters bob woodward and robert costa being outlandish with the final line