“It is true that the [Department of Defense] did message Philippines audiences questioning the safety and efficacy of Sinovac,” Pentagon officials wrote to their Filipino counterparts in a letter dated June 25 and reported by Reuters on Friday.

According to the document, the Pentagon admitted that it “made some missteps in our COVID related messaging” but assured Manilla that it halted the operation in late 2021 and has since “vastly improved oversight and accountability of information operations”.

The operation in question began in 2020, after China announced it would distribute Sinovac shots in the Philippines free of charge. In an effort to counter this public relations boon for Beijing, the Pentagon ordered its psychological operations center in Florida to create at least 300 fake social media profiles to disparage the Chinese vaccine, a Reuters investigation revealed last month.

“COVID came from China and the VACCINE also came from China, don’t trust China!” read a typical post created by the psyops team, while another stated: “From China – PPE, Face Mask, Vaccine: FAKE. But the Coronavirus is real.”

Military officials involved in the campaign knew that their goal was not to protect Filipinos from an unsafe vaccine, but to “drag China through the mud”, a senior officer told Reuters.

The propaganda campaign soon spread beyond the Philippines, according to the report. Muslim audiences across Central Asia and the Middle East were told that Sinovac contained pork gelatin, and was therefore “haram”, or forbidden under Islamic law. The campaign forced Sinovac to release a statement insisting that the shot was “manufactured free of porcine materials”.

The Pentagon has not publicly acknowledged the letter to the Filipino military, and the governments of the US and the Philippines refused to comment on the matter to Reuters.

Last month, however, a Pentagon spokesperson told the news agency that the US military “uses a variety of platforms, including social media, to counter those malign influence attacks aimed at the US, allies, and partners”, and claimed that Washington was only responding to a Chinese “disinformation campaign to falsely blame the US for the spread of Covid-19″.

The Chinese Foreign Ministry told Reuters that it has long maintained that the US spreads disinformation about China.

In the Philippines, Reuters’ report prompted an investigation by the Senate Foreign Relations Committee. In a hearing last month, Senator Imee Marcos, who leads the committee, called the Pentagon campaign “evil, wicked, dangerous, [and] unethical”, and suggested that Manilla investigate whether it can take legal action against Washington.