There has been intense debate and political bickering over Chinese Covid-19 vaccines in recent months – in particular over how well they work. The controversy provides lessons for China as a newcomer to global vaccine development, an area where it wants to take a leading role. The first is to do with managing expectations. Even before the pharmaceutical firms had provided data from clinical trials, Chinese officials and company executives were making claims – saying there hadn’t been a single infection among people who travelled abroad after getting the experimental jabs. The claims were dubious since they were referring to people who were not part of the trials and it would have been difficult to trace all of them. There were also reports in international media to the contrary, that some vaccinated Chinese had in fact been infected. Trumpeting the experimental jabs so early, before the results were in, heightened public expectations and also created doubts. The second lesson is on clinical trials and transparency. Sinopharm and Sinovac are major drug makers that had been through the World Health Organization prequalification process for other vaccines, so safety and quality control wasn’t a problem. But they had little experience in developing new vaccines for the global market or conducting overseas clinical trials, something highlighted by the WHO reviewers in their comments. While the WHO approved one Sinopharm vaccine for emergency use, it said there was insufficient data on the elderly and under 18s. Approvals for Sinovac’s vaccine were delayed because of insufficient data, while chaotic disclosures from its trial partners sent confusing signals. This did nothing for public opinion on the Chinese drug makers, which must learn to work with other countries and follow the international playbook. Having overseas partners involved is actually helpful because it makes it harder for critics to accuse China of doctoring the data. Chinese health authorities also jumped the gun by approving vaccines for emergency use in the mainland before late-stage trials were completed or even started, highlighting differences in how drugs are evaluated in China compared to elsewhere, and most importantly on transparency. While Chinese drug makers were proactive about publishing papers on the first two stages of trials, for the phase 3 trials Sinopharm and CanSino just issued a press release with no details. Sinopharm only published data on one of its vaccines after 200 million doses had been administered worldwide. Added to this is China’s tight control of information, with pharmaceutical firms and scientists unable to comment on data without government approval. It all has side effects for the vaccine makers, and lessons need to be learned.