Stemirna Therapeutics is preparing to launch a global multi-site human trials of its Covid-19 vaccine soon as the firm pushes for the second Chinese-made shot based on mRNA technology to protect against the coronavirus. Li Hangwen, co-founder and chief executive of the Shanghai-based start-up, said the firm is capable of producing 400 million doses a year from its facilities in mainland China, broadening the options for China’s vaccination campaign once it receives an approval from local regulators. The company has received approvals to start clinical trials in Brazil, where a final-stage in Phase 3 testing is also allowed to be carried out. The trials, involving thousands of volunteers to study its efficacy and safety, would begin soon, he added, declining to be specific. Can China’s home-grown mRNA Covid-19 vaccine pass its final tests? “We will publish data for the Phase 1 trial (conducted in Laos) soon,” Li said in an interview with the South China Morning Post. “Our Phase 2 trial is going on smoothly there. We have high confidence in our vaccine’s efficacy and safety based on the data.” Global biotechnology players are racing to boost vaccine supply as governments seek to reopen their battered economies, even as the pandemic took a turn for the worse in recent weeks amid the spread of highly-infectious strains. The market for Covid-19 vaccines was worth US$137 billion in 2021 , according to one estimate. More than 418 million infections and 5.85 million deaths have been recorded globally since the outbreak, according to the World Health Organization. China, which adopts a zero-Covid strategy, had 101,449 infections and 4,636 fatalities since the outbreak in Wuhan in late 2019, causing catastrophic shutdowns and losses. Typical vaccines use either a dead, inactivated or weakened form of virus to jump-start the body’s natural defences. mRNA vaccines, however, rely on RNA to produce proteins similar enough to the virus to generate immune cells to fight the virus. Fosun Pharma unit, BioNTech to form joint venture to make up to 1 billion doses of Covid-19 vaccine in China China’s vaccination programme relies heavily on inactivated vaccines such as those produced by SinoVac and Sinopharm, but trials are now being carried out to see whether vaccines made using newer techniques can boost immunity. “The Chinese biotech industry has to seize the opportunity to develop the country’s own mRNA technologies,” said Meng Tianying, a senior executive at Shanghai-based consultancy Domo Medical. “If their Covid-19 vaccines were to prove successful, those start-ups would not only earn a big reputation, but have a bright business outlook since the technology can be applied to treat a broad range of diseases.” Two mRNA vaccines – one by Moderna and the other by Pfizer and BioNTech – have been widely used in developed countries to curb spread of the pathogen. Moderna and Pfizer resort to lipid nanoparticles (LNP) technology to deliver a variety of nucleic acids in vivo and in vitro. StemiRNA’s LPP (lipopolyplex) nano-delivery platform is a core-shell structure, with polymer-mixed mRNA as the core and lipids as the shell. “Compared with traditional LNP platforms that most companies are adopting, the core-shell structured LPP particle is better at protecting mRNA, and is able to release mRNA gradually as the polymers are degraded,” said Shen Haifa, StemiRNA’s chief technology officer. Li, who obtained his doctorate in cancer biology from MD Anderson Cancer Centre of the University of Texas in 2010, founded Stemirna in Zhangjiang Hi-tech Park in 2016. It is developing more than 10 mRNA therapeutics drugs or vaccines, with the Covid-19 shot likely to be the first to be commercialised, he said in the interview. The firm has more than 500 employees. It raised US$200 million in June 2021 from investors including China Merchants Group, Sequoia Capital China, OrbiMed, GT Fund and Wuxi AppTec to fund its clinical trials and plant construction. Its production lines at Zhoupu and Fengxian in Shanghai are capable of making 200 million doses each. Stemirna has submitted applications to conduct clinical trials for its vaccine candidate in mainland China, Li added. The start-up’s yet-unnamed shot is the second mRNA vaccine from China. ARCoVax, the first, is jointly developed by the Academy of Military Medical Sciences, Suzhou Abogen Biosciences and Walvax Biotechnology. It is still doing phase 3 trials outside China, having conducted human trials in Mexico and Indonesia in 2021. For human trials in Brazil, Stemirna has options to decide to either use its vaccine as regular shots or boosters, CEO Li said. Mixing vaccines is believed in principle to generate better immune responses, according to researchers. “Stemirna is in a front-running position among domestic Chinese companies in preparing production for mRNA vaccines,” Li said. “Our vaccine is an updated version targeting variants of Covid-19 pandemic that are different from the wild type. Studies and early trials showed that initial results are encouraging.”