None of the four Chinese vaccines were supported by the WHO and the Coalition for Epidemic Preparedness Innovations (CEPI) working for global access to Covid-19 vaccines even after Beijing joined Covax. Apart from lack of data, there could also be risk bias involving subjects injected with the candidate vaccines, some researchers said. If there were safety concerns on Chinese vaccines, there were also some issues involving some of the Western-developed vaccines, like the United Kingdom's AstraZeneca, which has offered to sell its product without profit. Galvez said AstraZeneca was making available its vaccine for $5 per shot or $10 for a minimum of two shots, or less than P500 per person. AstraZenaca had initial problems in human trials in South Africa after some side effects were observed in a trial subject. Like China's vaccine, it also resumed trials after a week of suspension in September.