MD Reports has obtained and analysed a trove of Argentinian regulatory and trial documents, together with internal correspondence from the European Medicines Agency, revealing serious failures in the conduct and oversight of Pfizer’s pivotal phase III Covid-19 vaccine trial.
Previously undisclosed records expose medication errors, deficiencies in participant safety monitoring, conflicting assessments of serious adverse events and an independent ethics committee formally sanctioned over failures to protect research participants.
At the centre of the investigation is Site 1231, a hospital in Buenos Aires that recruited nearly 5,800 volunteers — approximately 13% of the entire trial — making it one of Pfizer’s largest research centres.
Argentina’s drug regulator documented 20 findings of non-compliance, but Europe’s medicines regulator later cited those same inspection records as evidence that the site had complied with international standards.
The documents reveal what Pfizer and international regulators knew, how they responded and how the European Medicines Agency ultimately closed its investigation without obtaining the further answers it had sought from Argentina.