The possibility that SARS-CoV-2 resulted from a laboratory accident has gained a degree of plausibility among several world leaders.

But China has rejected calls for further investigation into the matter, saying such allegations disregard “common sense,” as Zeng Yixin, vice-minister of the National Health Commission (NHC), said at a press briefing.

White House press secretary Jen Psaki criticized China’s stance, adding in a press briefing that “their position is irresponsible and, frankly, dangerous.”

China has also entertained a theory that Fort Detrick, an Army base in Maryland, is the source of the pandemic.

While the Fort Detrick lab researches infectious viruses, there is no evidence it is the outbreak’s source.

After initially discounting the possibility of the lab-leak scenario, the WHO has recommended further studies in China. Recently, the organization sought to audit laboratories and markets in Wuhan.

The investigation into the pandemic’s origins appears to have reached a standstill for at least the time being.

With little data on which to base their conclusions, WHO continues to entertain a range of theories. Many scientists initially assumed that the virus jumped from an animal to humans at a market in Wuhan.

Chinese officials have previously dismissed the theory that SARS-CoV-2 escaped from a lab there as politically motivated.