An inquiry of the Philippine Senate into a secret US military propaganda operation in the Philippines that aimed to discredit China's vaccines at the height of the COVID-19 pandemic can clear disinformation and help future decisions on public health, analysts said.

Tuesday's inquiry was led by Senator Imee Marcos, head of the Senate's Foreign Relations Committee and elder sister of Philippine President Ferdinand Marcos Jr.

Reuters reported on June 14 how the Pentagon ran a clandestine influence campaign in 2020 and 2021 to sow doubt about Sinovac vaccines and other pandemic-related aid from China across the developing world.

Obstructing China's assistance to the Philippines in vaccines and anti-epidemic supplies, the United States military even resorted to impersonating Filipinos on the internet and using all means to spread rumors and smear Chinese vaccines, the report said.

Imee Marcos said the disinformation campaign against Sinovac — one of the more accessible vaccines at the time — discouraged Filipinos from getting vaccinated and left them more vulnerable to COVID-19, local media reported.

"Disinformation had its malign effects. The numbers are shocking. We're talking about millions, hundreds of thousands," she said.

The hearing by the Philippine Senate is "a welcome development", said a spokesperson of the Chinese embassy in the Republic of the Philippines on Wednesday.

The Pentagon's moves were to serve the US' geopolitical self-interest of containing and suppressing China, while disregarding the lives and health of the vast majority of the Filipino people, the spokesperson said.

Anna Rosario Malindog-Uy, vice-president for external affairs of the Asian Century Philippines Strategic Studies Institute, said the outcome of this investigation could set a precedent for how the Philippines and other countries handle similar issues in the future.

"Depending on the findings, there could be long-term consequences for managing vaccine procurement and distribution, potentially leading to greater emphasis on transparency and independence in public health decisions," she said.

Malindog-Uy said the Philippine Senate investigation broadly made the Filipino public aware that the Pentagon's actions not only compromised their health and safety, but also set a dangerous example for future global health crises and international cooperation.

The Senate has a crucial role in shaping national policy, she said, that is why the outcome of the May 2025 election race will have long-term implications for future elections, including the 2028 presidential race.

In a separate development, Vice-President Sara Duterte told reporters on Wednesday that her father and two brothers — Paolo and Sebastian — "are raring to run" in the Senate election next May.

She made this announcement a few days after resigning from President Marcos' cabinet. Rodrigo, Paolo and Sebastian Duterte have not released any statement yet regarding her announcement.

Sara's announcement "is a testament to the strategic acumen of the Duterte family", Malindog-Uy said. "It conveys to their supporters and the broader Filipino public that the Duterte family maintains a cohesive and unified stance on all significant national issues."

Jean Encinas-Franco, a political science professor at the University of the Philippines, cited the power of name recall and how this benefits the "Duterte brand".

"The 'Duterte brand' represents authenticity, malasakit (concern), the macho brand of politics that Filipinos like," Encinas-Franco said.