China’s health authorities have approved clinical trials of two Covid-19 vaccines that use mRNA, potentially adding an option to the nation’s arsenal in its battle against the pandemic’s worst outbreak since 2020. CanSino Biologics and CSPC Pharmaceutical have been approved by the National Medical Products Administration of China (NMPA) to commence trials, according to statements by the two companies. CanSino’s stock price in Hong Kong closed 5.9 per cent higher at HK$132.90 on Monday morning. CSPC Pharmaceutical gained 5.2 per cent to HK$9.30. The approvals add CanSino and CSPC to the race among Chinese companies to use messenger ribonucleic acid (mRNA) for generating immune cells to fight the coronavirus, possibly offering viable alternatives to the vaccines already in production by international peers Pfizer BioNTech and Moderna. One mRNA vaccine called ARCoVax – developed by the Chinese Academy of Military Medical Sciences, Suzhou Abogen Biosciences and Walvax Biotechnology – is already in the final stages of global human trials. It comes as China battles its worst outbreak of the coronavirus in two years. The commercial capital of Shanghai is in lockdown, as the nation recorded 1,366 confirmed cases and 11,771 asymptomatic cases on Sunday. So far China has only allowed Covid-19 immunisation that employs conventional vaccine technology . It has only approved the use of jabs made by domestic firms such as Sinopharm and Sinovac. Traditional vaccines use either a dead, inactivated or weakened form of the 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 it. The country is developing a number of its own mRNA vaccines to deploy instead of those produced by international peers. Earlier, Shanghai-based start-up Stemirna Therapeutics was also approved to start clinical trials in Brazil, with a production capability of 400 million doses a year from its facilities in mainland China. “We will proceed with at least three phases of trials,” a CanSino spokesperson told the Post . There is a possibility an additional one or two more phases of trials may be required before the vaccine is approved for launch, the spokesperson added. Regulators around the world typically require three phases of clinical trials to evaluate a vaccine candidate before giving approval. Phase four studies, conducted after a vaccine is licensed, is carried out to further test its safety and efficacy in a wider population over a longer time period, according to the World Health Organization. CanSino said its vaccine can induce superior neutralising antibodies against multiple variants identified by the WHO. “Compared with the current original strain-based Covid-19 vaccines, our Covid-19 mRNA vaccine can elicit neutralising antibodies with better cross-variant reactivity,” the company said in a filing to the Hong Kong stock exchange. “[It] is expected to provide more effective protection against infections caused by circulating variants.” CSPC, meanwhile, said preclinical studies showed its vaccine candidate can generate high neutralising activity against variants including the Omicron and Delta strains. The product has good stability when stored long-term at 2-8 degrees Celsius, it added. A non peer-reviewed study published in September 2021 on medRxiv.org found that a CanSino vaccine made using a vector virus as a booster was significantly more immunogenic than an inactivated vaccine.