The completion date of a BioNTech coronavirus vaccine study in China has been postponed for a second time, according to records on a clinical trial database. The trial was initially expected to end December last year but was delayed until April and now October, according to an update on ClinicalTrials.gov, a database by the National Library of Medicine in the United States that tracks clinical trials around the world. The phase 2 study of 950 healthy individuals aged between 18 and 85 was launched in December 2020 to measure participants’ antibody levels and follow up on side effects. The results will be used to support future biologic licence applications in China, according to vaccine developer BioNTech . The summary of the study said “the trial for each participant will last for approximately 13 months”. The study is directed by the German vaccine developer BioNTech in collaboration with its Greater China distributor Shanghai-based Fosun Pharma and conducted by the Jiangsu Provincial Centre for Disease Control and Prevention. The Pfizer-BioNTech mRNA jab is the most widely used Covid-19 vaccine in the world, with more than 6 billion doses supplied globally, according to the Unicef Covid-19 Vaccine Market Dashboard. So far, the most effective vaccines have been mRNA jabs from Pfizer/BioNTech and US company Moderna. China has relied on inactivated vaccines – which use traditional technology but are generally less effective against the Omicron and Delta variants – to protect its population against the virus. No overseas-developed mRNA vaccines have been approved by the Chinese regulator. Shanghai-based Fosun Pharma has come the closest, winning a recommendation from the government’s expert panel in July for the Pfizer/BioNTech jab. Fosun has exclusive rights to distribute the Pfizer/BioNTech vaccine in Greater China, but supply has been restricted to Hong Kong, Macau and Taiwan while it awaits regulatory approval – the next and final step after the expert panel’s endorsement. In March, Fosun Pharma chief executive Wu Yifang said the vaccine was still in the process of seeking approval, according to Beijing-based newspaper The Economic Observer . China is developing a number of its own mRNA vaccines to use instead of those produced overseas. In April, the country’s health authorities approved clinical trials of two mRNA Covid-19 vaccines – one by CanSino Biologics and the other by CSPC Pharmaceutical. Another called ARCoVax – developed by the Chinese Academy of Military Medical Sciences, Suzhou Abogen Biosciences and Walvax Biotechnology – is already in the final stages of international human trials. Jin Dong-Yan, a virologist with the University of Hong Kong, said the BioNTech vaccine had been proven to be safe and effective in global trials and mass rollouts, and not having it in China was not beneficial to the people. “If [Chinese authorities] respect lives and want to protect the health of the people, they should approve the vaccine without any delay,” he said. Jin said other approved Chinese vaccines, including the widely used Sinopharm and Sinovac jabs, conducted their trials overseas when China was largely free of Covid-19. “The only concern [Chinese authorities] raised was side effects. But the BioNTech vaccine has been used in billions of people,” he said, adding that results from overseas trials could support its launch in China. He also said it was uncommon for ongoing studies to be postponed although it is not clear why this study was delayed.