- Former ANMAT director Nélida Agustina Bisio, who oversaw Pfizer's COVID-19 vaccine trial in Argentina, has been charged in connection with 90 deaths from contaminated fentanyl.
- ANMAT inspectors found 28 critical safety issues at the lab producing the fentanyl but failed to stop distribution.
- The lab lost 25% of its fentanyl citrate powder—3 kilograms—in the production process.
- A federal judge ordered Bisio's assets frozen at 500 billion pesos ($330 million).
- Investigative journalist Federico Dario Teijeiro uncovered evidence of bribery and systemic regulatory failures.
The deadly batch: How contaminated fentanyl reached patients
In May 2025, 15 people at a single Argentine hospital died on the same day. Hospital staff were baffled—the patients were being treated on different floors for different conditions. The common thread? All had received fentanyl from Laboratorios Ramallo, a lab that had been flagged with nearly 30 critical safety violations by ANMAT inspectors just months earlier.
By the time the crisis ended, at least 90 people were dead and 44 others suffered serious injuries. The contaminated fentanyl contained Klebsiella pneumoniae and Ralstonia mannitolilytica bacteria. Federal Judge Ernesto Kreplak has now charged former ANMAT director Nélida Agustina Bisio and her subordinate Gabriela Mantecón Fumadó with adulteration of medicinal substances.
Regulatory capture: A pattern of looking the other way
ANMAT—Argentina's equivalent of the U.S. FDA—conducted inspections in November and December 2024 at Laboratorios Ramallo, uncovering 28 critical problems. Yet the agency took no meaningful action. Mantecón Fumadó drafted a warning letter to the lab in January 2025 but waited until February to send it—the "softest measure" available to the agency, according to journalist Teijeiro.
The lab's records showed 25% of its fentanyl citrate powder—3 kilograms—simply disappeared during production. No credible business operates with such losses, Teijeiro noted. The missing powder could have been sold on the black market, stolen by employees, or consumed by workers.
Rather than halting distribution, ANMAT allowed the tainted drug to continue reaching hospitals. A federal judge had to order the recall after patients began dying.
The Pfizer connection: Same officials, different crisis
This is the second federal lawsuit against Bisio. The first alleges she helped Pfizer cover up at least one death and one heart injury sustained by clinical trial participants for the COVID-19 vaccine.
ANMAT recorded 20 findings during its inspection of the Pfizer trial at Buenos Aires' Central Military Hospital, including 52 participants receiving double the planned vaccine dose. Principal investigator Fernando Polack simultaneously served as president of I TRIALS SA, the company administering payments for the trial.
The Central Ethics Committee of Buenos Aires later categorized five types of non-compliance as "serious," including failures in adverse-event follow-up and 439 pending deviation reports that Pfizer had not submitted to the ethics committee.
When profit trumps safety
The pattern echoes a troubling history. In 1968, during the Hong Kong flu outbreak, children received untested penicillin and streptomycin vaccines, leaving many permanently deaf. When profit incentives override safety protocols, shortcuts become institutionalized.
Teijeiro's investigation uncovered evidence that ANMAT leaders received bribes from labs and food producers to ignore problems. The agency's culture of looking the other way—doing things "for show" without meaningful action—has now cost dozens of lives.
Global implications
Before the fentanyl deaths became public, the U.S. FDA and ANMAT were negotiating an agreement on medicine exchange between the countries. Those negotiations halted after the revelations.
"Everyone assumes the FDA has reviewed data," said one petitioner in a separate U.S. case challenging COVID vaccine labeling. "Buyer beware." The same warning now applies to Argentina's pharmaceutical oversight.
A system that failed
Judge Kreplak determined that Bisio maintained a "passive and permissive" attitude while Mantecón Fumadó "had full knowledge of the malfunctioning of the laboratories" yet delayed warnings and held informal meetings with lab executives rather than enforcing regulations.
Both former officials remain free on bail, their assets frozen at 500 billion pesos each. Their prosecution marks a rare instance of accountability in a system where regulators often escape consequences for failures that cost lives.
As Teijeiro put it: The real clinical trial is happening in the real world, in real-time. Honest communication and transparency remain the only path to regaining public trust—but Argentina's regulatory system has yet to learn that lesson.
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