In the pages of The BMJ a decade ago, in the middle of a different pandemic, it came to light that governments around the world had spent billions stockpiling antivirals for influenza that had not been shown to reduce the risk of complications, hospital admissions, or death. The errors of the last pandemic are being repeated. Memories are short. Today, despite the global rollout of covid-19 vaccines and treatments, [the] data underlying the trials for these new products remain inaccessible to doctors, researchers, and the publicand are likely to remain that way for years to come. This is morally indefensible for all trials, but especially for those involving major public health interventions. Pfizer's pivotal covid vaccine trial was funded by the company and designed, run, analysed, and authored by Pfizer employees. The company and the contract research organisations that carried out the trial hold all the data. And Pfizer has indicated that it will not begin entertaining requests for trial data until May 2025, 24 months after the primary study completion date. The lack of access to data is consistent across vaccine manufacturers. Regulators and public health bodies could release details such as why vaccine trials were not designed to test efficacy against infection and spread of SARS-CoV-2. Had regulators insisted on this outcome, countries would have learnt sooner about the effect of vaccines on transmission and been able to plan accordingly.