Thu. Jan 20th, 2022

China’s race to develop its own messenger RNA vaccine has gained greater urgency as Beijing struggles to curb an outbreak of the Omicron coronavirus variant that threatens its zero-covid policy.

Beijing’s pandemic strategy, in which authorities impose strict closure measures on communities with local cases to stem any outbreak, according to China’s official statistics, prove effective to prevent the large number of deaths in some Western countries.

But it has China left isolated of the rest of the world and confined millions of its own citizens to their homes to prevent the virus from spreading.

Progress towards a domestic mRNA vaccine in China was slow, as the country’s pharmaceutical companies initially chose to use traditional inactivated virus technology in vaccines.

In November, Chinese biotechnology company Suzhou Abogen Biosciences and its partner Walvax Biotechnology received regulatory approval to test their mRNA vaccine candidate in a booster trial. Their vaccine deploys the same type of technology used in the Moderna and BioNTech / Pfizer jabs, which offer higher levels of protection against the Omicron variant than existing Chinese-made shots.

Jerome Kim, director general of the International Vaccine Institute in South Korea, said Chinese pharmaceutical companies had opted for the “old-fashioned [inactivated] vaccine ”because the“ existing technology was readily available and used in vaccines that vaccinated billions of people ”.

But researchers maintain that this method is a weaker immune response as mRNA and viral vector vaccines, which cause a targeted response to the virus’ peak protein when it invades human cells, compared to the inactivated vaccine, which attacks many viral proteins.

China administered 2.8 billion doses of Sinopharm and Sinovac’s inactivated virus vaccines to 1.2 billion people. But the restriction of 13 million inhabitants in Xi’an, where more than 1,758 cases have occurred in China’s worst outbreak since the start of the pandemic in Wuhan in the past month, officials stressed a lack of confidence in domestic jabs.

“The lower efficacy of Chinese vaccines indicates that most people do not have the necessary neutralizing antibodies to prevent infection or serious cases,” said Jin Dong-yan, a virologist at the University of Hong Kong.

Research of the university showed that two pricks and a booster of Sinovac’s vaccine provide insufficient protection against the Omicron variant, while another study showed that the efficacy of both Chinese vaccines decreased rapidly.

In November, Chinese academics published a study warning that moving away from Beijing’s strict zero-covid policy to one similar to the US would overwhelm the medical system and mean a disaster for the country.

The low efficacy of Chinese vaccines has had repercussions beyond its borders, as Beijing fired 1.49 billion shots. A study of 185 non-peer-reviewed health care workers in Thailand found that 60 percent of Sinovac stimulus recipients had high levels of neutralizing antibodies one month after receiving their second sting, but that figure dropped after three months. dropped to 12 percent. .

Even as evidence of the poorer performance of its vaccines increases, Chinese regulators have refrained from granting approval to the BioNTech mRNA vaccine. The German drugmaker tried to enter the Chinese market by a distribution partnership with China’s Fosun Pharma.

Calvin Ho, a bioethicist at the University of Hong Kong, said Beijing did not recognize vaccines developed by foreign pharmaceutical companies because it wanted to support homemade alternatives.

Investors hope the Walvax and Abogen vaccine, developed with researchers from a Chinese military medical institute, will not face the same political obstacles. Last year, Abogen, founded in 2019 and headquartered in Suzhou, west of Shanghai, raised $ 1.1 billion from supporters, including Temasek, the Singapore state-funded investment fund, and investment firm Invesco.

Beijing has never approved mRNA products for therapeutic use, which has put local medicine companies on the back foot as the strength of the technology became apparent during the pandemic.

A leading Chinese expert on respiratory diseases, Zhong Nanshan, said last month that China must “learn from other countries in areas they have done well, such as mRNA vaccines. They have spent years developing them and have succeeded in to produce mRNA vaccine within a few months. ”

Jin of Hong Kong University said that because China was slow to develop mRNA technology, its pharmaceutical companies did not have the scientific knowledge and specialized machinery to deliver the stitch on scale.

He added that there are significant technical barriers to making lipid nanoparticles, the fatty shield that protects fragile mRNA molecules when human cells invade, which is difficult to create safely and in large quantities.

But Kim said it was only a “matter of time” before China had access to an mRNA vaccine and that the safe and efficient LNPs were available to be licensed if local companies could not produce their own.

Pre-clinical trial data showed that the Walvax and Abogen vaccine candidate, called ARCoV, produced a strong antibody action against coronavirus during the animal testing phase. No data on the more conclusive later-stage trials on human subjects were published.

But even if China rolls out an mRNA vaccine as a booster, experts have warned that it may not be a silver bullet that gives authorities the confidence to end its zero-Covid policy.

An unnamed Beijing immunology professor said that even if China rolled out its own mRNA vaccine, “it would not have a major impact on China’s pandemic controls”, as evidence of existing versions of the stitch. that breakthrough infections are still possible.

Additional report by Maiqi Ding in Beijing and John Burn-Murdoch in London

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