The conventional wisdom about the coronavirus pandemic’s origins has changed rapidly, as conventional wisdom often does. Even skeptics and apologists have finally begun to acknowledge the Chinese Communist labs in Wuhan as a possible — even the likely — source of this plague.

But those with open eyes and an open mind could see from the beginning that this virus might have spilled out of a lab. Last January, I pointed out that the outbreak’s supposed epicenter, a food market, was just miles from the Wuhan Institute of Virology (WIV), China’s highest-security facility for deadly pathogens. A second lab, the Wuhan Center for Disease Control, was only a few hundred yards from the market. And many of the earliest known cases had no contact with the market. Thus, I urged U.S. officials to investigate the labs — and warned that this epidemic could be a man-made disaster worse than Chernobyl.

Other early known facts also pointed to a lab origin. The suspected host animal, the Chinese horseshoe bat, does not live in or around Wuhan. But the WIV and the Wuhan CDC worked with bat coronaviruses. Researchers at the WIV traveled to remote caves in Yunnan Province, the site of a small but deadly viral outbreak in 2012, to capture bats and sift their guano for new viruses. They also kept live bats in captivity — flying petri dishes that can bite, scratch, and bleed on unwary researchers. Finally, China has a history of lab leaks, such as the accidental release of the SARS coronavirus from government laboratories in 2003 and 2004; a similar leak in Wuhan could not be ruled out.

The events and discoveries of the past year have only bolstered the lab-leak hypothesis.

First, the Chinese government has not behaved like an innocent victim. Instead, it has acted consistently as if it’s covering up a terrible secret in Wuhan. In December 2019, the WIV’s infamous bat expert, Dr. Shi Zhengli, deleted data and purged phrases such as “wild animal samples,” “cross-species infection,” and “emerging infectious diseases” from institute databases. The next month, the Chinese government installed its top military epidemiologist at the WIV, putting it under the control of the People’s Liberation Army. Last February, Chairman Xi Jinping announced that China would fast-track legislation to reform the nation’s biosecurity laws. Chapter Five of that law addresses “biosafety of pathogenic microorganism laboratories” — in other words, lab leaks. And the Chinese government purged hundreds of studies relating to bat-coronavirus research, including research by Dr. Shi.

We’ve also learned more about the U.S. government’s concerns about the Wuhan lab. Last year, journalist Josh Rogin reported on State Department warnings from 2018 about lax safety standards and a shortage of trained personnel at the WIV. Earlier this month, the Wall Street Journal disclosed an intelligence report stating that three researchers there went to the hospital with coronavirus-like symptoms in November 2019 — one month before the first confirmed case.

Further, the inability to find the host species in nature is a dog that hasn’t barked. It took only four months to find the host for SARS, and nine months for MERS. Yet more than 15 months on, Beijing hasn’t identified the host species for this coronavirus — something for which they’ve surely searched high and low.

But despite it all, pundits, politicians, and activists in white lab coats denounced the lab-leak hypothesis for more than a year as a dangerous and possibly racist conspiracy theory. This denialism had real-world consequences. The World Health Organization’s report on the virus’s origins dismissed the hypothesis even without adequate access to the labs, their employees, or their records. The Biden administration reportedly scuttled a working group at the State Department investigating the possibility of a lab leak.

Curiously, some of the loudest critics have recently executed the sharpest about-face. In March, the WHO’s director-general admitted that the theory “requires further investigation.” President Biden also executed a U-turn, directing intelligence agencies to “redouble their efforts” to determine the virus’s origin.

Others can speculate on what inspired these sudden conversions. The important thing now is that the lab-leak hypothesis is getting the attention it deserves. The world may be ready to take an honest look at what caused this devastating pandemic.

We must insist that the Chinese government open the WIV and the Wuhan CDC to a reputable, international team of investigators, with full access to health records, inventories of animal-test subjects, samples, viruses, and the research conducted at the lab. Investigators must also visit other critical sites barred to researchers, such as the Yunnan mines where the nearest wild relatives to the virus were discovered.

Of course, Chinese Communists will almost certainly refuse these requests, in which case we should encourage foreign scientists who’ve worked with the WIV to come forward with what they know. And China’s continued stonewalling itself should further validate the lab-leak hypothesis.

Finally, we need transparency on the “gain-of-function” research conducted at the WIV. Sadly, some of this information must come from the U.S. government. It’s a matter of public record that the National Institutes of Health funded research at the WIV, which Dr. Anthony Fauci disputed until very recently.

Perhaps the world will never know conclusively where this virus originated; it has become a cliché to say so. But we already know a lot, and it all points toward a deadly combination of Chinese negligence and malevolence. The American people deserve our best answer, and for that we must go to the source: The Wuhan labs are the prime suspects, as they have been from the very beginning.