a laboratory setting. History of Zoonotic Pathogen Emergence, Conditions in China Ripe for Zoonotic Spillover Analysts that find the natural zoonotic spillover hypothesis the most likely explanation for the pandemic also note the wide diversity of animals that are susceptible to SARS-CoV-2 infection, range of scenarios—to include animal trafficking, farming, sale, and rescue—in China that would enable zoonotic [ 7 ] transmission, and precedent of novel human infectious disease outbreaks originating from zoonotic transmission. Previous human coronavirus outbreaks, to include SARS-CoV-1 and Middle East Respiratory Syndrome coronavirus (MERS-CoV), occurred naturally and were linked to animal reservoirs with zoonotic transmission to humans, according to scientific literature. · Extensive wildlife and livestock farming, wildlife trafficking, and live animal markets in China and historically lax government regulation—and even promotion—of these activities increase the probability that initial transmission occurred along one of these routes. · Academic literature has revealed Wuhan markets sold live mammals and dozens of species—including raccoon dogs, masked palm civets, and a variety of other mammals, birds, and reptiles—often in poor conditions where viruses can jump among species, facilitating recombination events and the acquisition of novel mutations. SARS-CoV-2 can infect a range of mammals, including cats, dogs, pangolins, minks, raccoon dogs, and a variety of wild and domestic animals, according to academic literature. · Wider Hubei Province has extensive farming and breeding of animals that are susceptible to SARS-CoV-2, including minks and raccoon dogs. [ 8 ] These analysts note that there is a precedent for viral vectors to travel long distances in China and cause infection elsewhere because of transportation and trade nodes, thereby widening and complicating the search for the specific zoonotic spillover incident. For instance, the bat coronavirus that is currently the closest known relative to the original SARS-CoV-1 was identified in Yunnan Province, even though the first SARS outbreak detected in humans occurred in Guangdong Province, hundreds of kilometers away. The Case for the Laboratory-Associated Incident Hypothesis One IC element assesses with moderate confidence that COVID-19 most likely resulted from a laboratoryassociated incident involving WIV or other researchers—either through exposure to the virus during experiments or through sampling. Some analysts at elements that are unable to coalesce around either explanation also assess a laboratory origin with low confidence. These analysts place emphasis on academic articles authored by WIV employees indicating that WIV scientists conducted research on other coronaviruses under what these analysts consider to be inadequate biosafety conditions that could have led to opportunities for a laboratory-associated incident. These analysts also take into account SARS-CoV-2’s genetic epidemiology and that the initial recorded COVID-19 clusters occurred only in Wuhan—and that WIV researchers who conducted sampling activity throughout China provided a node for the virus to enter the city. WIV Research Includes Work With Animals That Carry Relatives of SARS-CoV-2 The analysts that find the laboratory-associated origin theory most likely assess that WIV researchers’ inherently risky work with coronaviruses provided numerous opportunities for them to unwittingly become infected with SARS-CoV-2. Although the IC has no indications that WIV research involved SARS-CoV-2 or a close progenitor virus, these analysts note that it is plausible that researchers may have unwittingly exposed themselves to the virus without sequencing it during experiments or sampling activities, possibly resulting in asymptomatic or mild infection. Academic literature indicates that WIV researchers conducted research with bat coronaviruses or collected samples from species that are known to carry close relatives of SARS-CoV-2. · Based on currently available information, the closest known relatives to SARS-CoV-2 in bats have been identified in Yunnan Province, and researchers bringing samples to laboratories provide a plausible link between these habitats and the city. · These analysts also note that China’s investigations into the pandemic’s origin might not uncover evidence of a laboratory-associated incident if it involved only a small number of researchers who did not acknowledge or have knowledge of a potential infection. Biosafety Conditions for Specific Work Could Have Led to an Incident The analysts that assess COVID-19 most likely originated from a laboratory-associated incident also place emphasis on information suggesting researchers in China used biosafety practices that increased the risk of exposure to viruses. Academic publications suggest that WIV researchers did not use adequate biosafety precautions at least some of the time, increasing the risk of a laboratory-associated incident. WIV Illnesses in Fall 2019 Not Diagnostic The IC assesses that information indicating that several WIV researchers reported symptoms consistent with COVID-19 in autumn 2019 is not diagnostic of the pandemic’s origins. Even if confirmed, hospital admission alone would not be diagnostic of COVID-19 infection. [ 9 ] The Role of the