2020 for sanitation and disinfection. the chinese center for disease control and prevention (ccdc) entered the market the same day and took samples; as the animals had been removed before public-health authorities came in, no animals were sampled, although that would have been more conclusive. in april 2020, china imposed restrictions on publishing academic research on the novel coronavirus. investigations into the origin of the virus would receive extra scrutiny and must be approved by central government officials. the restrictions do not ban research or publication, including with non-chinese researchers; ian lipkin, a us scientist, has been working with a team of chinese researchers under the auspices of the chinese center for disease control and prevention, a chinese government agency, to investigate the origin of the virus. lipkin has long-standing relationships with chinese officials, including premier li keqiang, because of his contributions to rapid testing for sars in 2003. the huanan live-animal market was suspected of being the source of the virus, as there was a major, early cluster of cases there. on 31 january 2021, a team of scientists led by the world health organization visited the market to investigate the origins of covid-19. based on the existing evidence, the who concluded that the origin of the virus was still unknown, and the chinese government insisted that the market was not the origin. the chinese government has long insisted that the virus originated outside china, and until june 2021 denied that live animals were traded at the huanan market. some chinese researchers had published a preprint analysis of the huanan swab samples in february 2022, concluding that the coronavirus in the samples had likely been brought in by humans, not the animals on sale, but omissions in the analysis had raised questions, and the raw sample data had not yet been released. on march 4th of 2023, the data from the swab samples of the huanan live-animal market were released, or possibly leaked; a preliminary analysis of this data was reviewed by the international research community, which said that it made an animal origin much more likely. although the samples do not definitively prove that the raccoon dog is the "missing" intermediate animal host in the bat-to-human transmission chain, it does show that common raccoon dogs were present in the huanan market at the time of the initial sars-cov-2 outbreak, in areas that were also positive for sars-cov-2 rna, and substantially strengthens this hypothesis as the proximal origin of the pandemic. an attempt by these researchers to collaborate with the chinese researchers was not answered, but the raw data was removed from the online database. on march 14th, an international group of researchers presented a preliminary analysis at a meeting of the world health organization’s scientific advisory group for origins of novel pathogens, at which chinese covid-19 researchers were also present. on the sixteenth, george gao, the former head of the ccdc and lead author on the february 2022 preprint, told science that there was "nothing new" in the raw data, and refused to answer questions about why his research team had removed it from the database. on the 17th of march, the who director-general said that the data should have been shared three years earlier, and called on china to be more transparent in its data-sharing. there exists further data from further samples which has not yet been made public. maria van kerkhove, the who’s covid-19 technical lead, called for it to be made public immediately (see huanan live-animal market#swabs). trump administration on 6 february 2020, the director of the white house's office of science and technology policy requested the national academies of sciences, engineering, and medicine to convene a meeting of "experts, world class geneticists, coronavirus experts, and evolutionary biologists", to "assess what data, information and samples are needed to address the unknowns, in order to understand the evolutionary origins of covid-19 and more effectively respond to both the outbreak and any resulting information". in april 2020, it was reported that the us intelligence community was investigating whether the virus came from an accidental leak from a chinese lab. the hypothesis was one of several possibilities being pursued by the investigators. us secretary of defense mark esper said the results of the investigation were "inconclusive". by the end of april 2020, the office of the director of national intelligence said the us intelligence community believed the coronavirus was not man-made or genetically modified. us officials criticised the "terms of reference" allowing chinese scientists to do the first phase of preliminary research. on 15 january 2021, us secretary of state mike pompeo said that to assist the who investigative team's work and ensure a transparent, thorough investigation of covid-19's origin, the us was sharing new information and urging the who to press the chinese government to address three specific issues, including the illnesses of several researchers inside the wiv in autumn 2019 "with symptoms consistent with both covid-19 and common seasonal illnesses", the wiv's research on "ratg13" and "gain of function", and the wiv's links to the people's liberation army. on 18 january, the us called on china to allow the who's expert team to interview "care givers, former patients and lab workers" in the city of wuhan, drawing a rebuke from the chinese government. australia also called for the who team to have access to "relevant data, information and key locations". a classified report from may 2020 by the lawrence livermore national laboratory, a us government national laboratory, concluded that the hypothesis that the virus leaked from the wiv "is plausible and deserves further investigation", although the report also notes that the virus could have developed naturally, echoing the consensus of the american intelligence community, and provides no "smoking gun" towards either hypothesis. biden administration on 13 february 2021, the white house said it had "deep concerns" about both the way the who's findings were communicated and the process used to reach them. mirroring concerns raised by the trump administration, national security adviser jake sullivan stated that it was essential that the who-convened report be independent and "free from alteration by the chinese government". on 14 april 2021, the director of national intelligence avril haines, along with other biden administration officials, said that they had not ruled out the possibility of a laboratory accident as the origin of the covid-19 virus. on 26 may 2021, president joe biden directed the u.s. intelligence community to produce a report within 90 days on whether the covid-19 virus originated from a human contact with an infected animal or from an accidental lab leak, stating his national security staff said there is insufficient evidence to determine either hypothesis to be more likely. on 26 august 2021, the office of the director of national intelligence released an unclassified summary of their findings, with the main point being that the report remained inconclusive as to the origin of the virus, with intelligence agencies divided on the question. the report also concluded that the virus was most likely not genetically engineered, and that china had no foreknowledge of the virus prior to the outbreak. the report concluded that a final determination of the origin was unlikely without cooperation from the chinese government, saying their prior lack of transparency "reflect in part china's government's own uncertainty about where an investigation could lead, as well as its frustration that the international community is using the issue to exert political pressure on china." chinese foreign ministry spokesman wang wenbin said that the us intelligence report was "unscientific and has no credibility". on 23 may 2021, the wall street journal reported that a previously undisclosed us intelligence report stated that three researchers from the wuhan institute of virology became ill enough in november 2019 to seek hospital care. the report did not specify what the illness was. officials familiar with the intelligence differed as to the strength to which it corroborates the hypothesis that the virus responsible for covid-19 was leaked from the wiv. the wsj report notes that it is not unusual for people in china to go to the hospital with uncomplicated influenza or common cold symptoms. yuan zhiming, director of the wiv's wuhan national biosafety laboratory, responded in the global times, a chinese state media outlet, that the "claims are groundless". marion koopmans, a member of the who study team, described the number of flu-like illnesses at the wiv in 2019 as "completely normal". workers at the wiv must provide yearly serum samples. wiv virologist shi zhengli said in 2020 that, based on an evaluation of those serum samples, all staff tested negative for covid-19 antibodies. the house foreign affairs committee has investigated the origins of the pandemic, and heard classified briefings. the republican minority issued a report in august 2021 that they believed the origin of the pandemic was an accidental lab escape. the resurgence of the theory of a laboratory accident was fueled in part by the publication, in may 2021, of early emails between anthony fauci and scientists discussing the issue, before deliberate manipulation was ruled out as of march 2020. on 14 july 2021, the house committee on science, space and technology held the first congressional hearing on the origins of the virus. bill foster, an illinois democrat who chaired the hearing, said the chinese government's lack of transparency is not in itself evidence of a lab leak and cautioned that answers may not be known even after the administration produces its intelligence report. expert witnesses stanley perlman and david relman presented to the congressman different proposed explanations for the origins of the virus and how to conduct further investigations. on 16 july 2021, cnn reported that biden administration officials considered the lab leak theory "as credible" as the natural origins theory. in october 2022, an interim report of a republican member of a us senate committee concluded that a lab origin was most likely, but offered "little new evidence", according to the new york times. in february of 2023, the united states energy department updated its assessment on the origins of the virus, shifting from "undecided" to "low confidence" in favor of a laboratory leak. white house national security advisor jake sullivan responded to the report saying there was still "no definitive answer" to the pandemic origins' question. on february 28, 2023, the head of the federal bureau of investigation christopher wray said the fbi believes covid-19 most likely originated in the lab. world health organization the world health organization has declared that finding where sars-cov-2 came from is a priority and that it is "essential for understanding how the pandemic started." in may 2020, the world health assembly, which governs the world health organization (who), passed a motion calling for a "comprehensive, independent and impartial" study into the covid-19 pandemic. a record 137 countries, including china, co-sponsored the motion, giving overwhelming international endorsement to the study. in mid 2020, the world health organization (who) began negotiations with the government of china on conducting an official study into the origins of covid-19. in november 2020, the who published a two-phase study plan. the purpose of the first phase was to better understand how the virus "might have started circulating in wuhan", and a second phase involves longer-term studies based on the findings of the first phase. who director-general tedros adhanom said "we need to know the origin of this virus because it can help us to prevent future outbreaks," adding, "there is nothing to hide. we want to know the origin, and that's it." he also urged countries not to politicise the origin tracing process, saying that would only create barriers to learning the truth. phase 1 for the first phase, the who formed a team of ten researchers with expertise in virology, public health and animals to conduct a thorough study. one of the team's tasks was to retrospectively ascertain what wildlife was being sold in local wet markets in wuhan. the who's phase one team arrived and quarantined in wuhan, hubei, china in january 2021. members of the team included thea fisher, john watson, marion koopmans, dominic dwyer, vladimir dedkov, hung nguyen-viet, fabian leendertz, peter daszak, farag el moubasher, and ken maeda. the team also included five who experts led by peter ben embarek, two food and agriculture organization representatives, and two representatives from the world