WASHINGTON, June 16 (Xinhua) -- At the height of the COVID-19 pandemic, the U.S. military launched a secret misinformation campaign to discredit Chinese vaccines in the Philippines, a nation severely impacted by the deadly virus, drawing widespread condemnation from public health experts, a Reuters investigation has found.

This is the first time a media outlet has exposed this clandestine operation. "It aimed to sow doubt about the safety and efficacy of vaccines and other life-saving aid that was being supplied by China," said Reuters in the investigation released Friday.

Through phony internet accounts meant to impersonate Filipinos, the military's propaganda efforts morphed into an anti-vax campaign, it said, adding that social media posts decried the quality of face masks, test kits and the first vaccine that would become available in the Philippines -- China's Sinovac inoculation.

Reuters identified at least 300 accounts on X, formerly Twitter, that matched descriptions shared by former U.S. military officials familiar with the Philippines operation. Almost all were created in the summer of 2020 and centered on the slogan #Chinaangvirus, meaning China is the virus in Tagalog, a major language of the Philippines.

After Reuters asked X about the accounts, the social media company removed the profiles, determining they were part of a coordinated bot campaign based on activity patterns and internal data.

The military program started under former President Donald Trump and continued months into Joe Biden's presidency, Reuters found -- even after alarmed social media executives warned the new administration that the Pentagon had been trafficking in COVID misinformation.

A senior Defense Department official acknowledged the U.S. military engaged in secret propaganda to disparage China's vaccine in the developing world, but declined to provide details, Reuters said.

A spokesperson for the Philippines Department of Health said the "findings by Reuters deserve to be investigated and heard by the appropriate authorities of the involved countries." Some aid workers in the Philippines, when told of the U.S. military propaganda effort by Reuters, expressed outrage.

Briefed on the Pentagon's secret anti-vax campaign by Reuters, some American public health experts condemned the program, saying it put civilians in jeopardy for potential geopolitical gain.

"I don't think it's defensible," said Daniel Lucey, an infectious disease specialist at Dartmouth's Geisel School of Medicine. "I'm extremely dismayed, disappointed and disillusioned to hear that the U.S. government would do that," said Lucey, noting the effort to stoke fear about Chinese inoculations risked undermining overall public trust in government health initiatives.

According to the investigation, the Philippines had among the worst inoculation rates in Southeast Asia. Only 2.1 million of its 114 million population were fully vaccinated -- far short of the government's target of 70 million. In June 2021, COVID cases in the Philippines exceeded 1.3 million, and almost 24,000 Filipinos had died from the virus. The difficulty in vaccinating the population contributed to the worst death rate in the region.

Some Filipino healthcare professionals and former officials contacted by Reuters were shocked by the U.S. anti-vax effort, which they say exploited an already vulnerable citizenry.

"Why did you do it when people were dyingcrashsimulatoronline? We were desperate," said Dr. Nina Castillo-Carandang, a former adviser to the World Health Organization and the Philippines government during the pandemic. "We don't have our own vaccine capacity" and the U.S. propaganda effort "contributed even more salt into the wound," she noted.

"I'm sure that there are lots of people who died from COVID did not need to die from COVID," Esperanza Cabral, who served as health secretary under President Gloria Macapagal Arroyo, was quoted by Reuters as saying.

To implement the anti-vax campaign, the Defense Department overrode strong objections from top U.S. diplomats in Southeast Asia at the time, Reuters found. Sources involved in its planning and execution say that the Pentagon, which ran the program through the military's psychological operations center in Tampa, Florida, disregarded the collateral impact that such propaganda may have on innocent Filipinos.

"We weren't looking at this from a public health perspective," a senior military officer involved in the program was cited by Reuters as saying. "We were looking at how we could drag China through the mud."

In uncovering the secret U.S. military operation, Reuters interviewed more than two dozen current and former U.S. officials, military contractors, social media analysts and academic researchers. Reporters also reviewed Facebook, X and Instagram posts, technical data and documents about a set of fake social media accounts used by the U.S. military.■