A comprehensive report released by the US Senate has suggested that Chinese researchers may have commenced the development of two COVID-19 vaccines as early as November 2019, prior to the official declaration of the outbreak. The 300-page document, which supports the theory that the pandemic was the result of a laboratory leak and most likely originated from a "research-related incident" at the Wuhan Institute of Virology (WIV), has further fueled suspicions about China's potential cover-up of early outbreak cases.

The extensive report, submitted to Axios, asserts that the hypothesis of the virus originating from animal-to-human transmission in a market should no longer be regarded as the most probable explanation. It calls for proponents of the natural transmission theory to produce "clear and convincing evidence" to support their claims, adding that the majority of available information indicates that the pandemic was most likely the unintentional result of biosafety containment failures during vaccine research.

The document highlights the lack of critical evidence proving a natural spillover, even three years after the emergence of COVID-19, as well as anomalies between the virus and other diseases that have naturally transmitted from animals to humans. It also mentions that the bats carrying the virus closest to COVID-19 resided over 1,000 miles away from Wuhan, while the WIV had collected more than 200 coronaviruses and employees were photographed handling bats with insufficient protective gear.

The report states that a research-related incident aligns with the early epidemiology of COVID-19, which demonstrated rapid viral spread in Wuhan, and emphasizes that factors such as human errors, mechanical failures, animal bites, escapes, inadequate training, insufficient funding, and pressure for results can lead to the release of virulent pathogens from laboratories.

Nonetheless, the Senate report does not provide a definitive conclusion on the pandemic's origin. It calls for further information and urges governments, leaders, public health officials, and scientists to exhibit greater transparency, engagement, and responsibility in their efforts to address the COVID-19 pandemic and prevent future outbreaks.

In recent developments, the FBI director, Christopher Wray, has stated that the virus "most likely" leaked from the Wuhan lab, while the US Department of Energy, which supervises 17 US laboratories researching advanced biology, has concluded that a laboratory leak was the most probable cause, albeit with "low confidence." Meanwhile, the CIA remains divided between the lab leak and natural transmission theories, and the US national security adviser, Jake Sullivan, has acknowledged that a "definitive answer" is yet to be reached.