New Covid variants threaten China’s mRNA vaccine hopes

China is making progress in its efforts to develop a Covid-19 messenger RNA vaccine, but experts warn it risks being overtaken by rapid mutations in the Omicron coronavirus variant.

Beijing’s refusal to endorse foreign shots and the limited effectiveness of more traditional inactivated vaccines available from domestic companies means an mRNA vaccine is widely seen as essential to any change from the economically costly zero-Covid policy. of President Xi Jinping.

Analysts’ optimism about the prospects for Chinese mRNA vaccines has been fueled by recent trial results for a jab developed by start-up Suzhou Abogen Biosciences with Chinese pharmaceutical company Walvax Biotechnology and the country’s military.

According to results published in May, Abogen’s AWcorna vaccine generated antibodies against Omicron at levels 4.4 times higher than those induced by the inactivated vaccine produced by Sinovac, one of the two major vaccine suppliers in China.

Early data from Abogen “looks very positive,” said Ben Cowling, an epidemiologist at the University of Hong Kong.

Most of the Chinese public have been vaccinated with inactivated vaccines from Sinovac and the state-owned Sinopharm. The researchers said the technology produced a weaker immune response than mRNA vaccines, which target the virus’ spike protein.

In an effort to increase the uptake of vaccines, health officials in Beijing announced on Wednesday that the capital’s 21 million residents would have to from next week for the first time show evidence of vaccination against Covid to enter in public spaces such as cinemas and gymnasiums.

Helen Chen, head of China life sciences at LEK Consulting, said Abogen was “closest to completion” of nine mRNA vaccine candidates developed by or in partnership with Chinese pharmaceutical companies and in the pipeline. ‘clinical tests.

Abogen’s success could have implications beyond the country’s borders.

The company hopes it will be possible to store its jab at normal refrigerator temperatures, rather than requiring the specialized low-temperature equipment needed for mRNA vaccines produced by Moderna or BioNTech and Pfizer. This would greatly facilitate distribution in developing countries.

But experts said Abogen and other Chinese mRNA jabs were also designed for earlier Covid variants and may struggle to cope with the emergence of new BA.4 and BA.5 subvariants. Omicron. These strains have found ways to circumvent natural and vaccine-generated immunity and are rapidly becoming dominant in much of the world. Studies have shown that more fully vaccinated people have been infected with BA.4 and BA.5 than with earlier strains.

“There’s a huge learning curve when it comes to mRNA technology, and companies have to deal with a moving target with all these strains of Covid,” said James Bellush, medical science expert at RTW. Investments, based in New York.

Bellush said the emergence of new variants meant the Chinese mRNA shots certainly wouldn’t have the “shattering” efficacy against infection of the Moderna and Pfizer shots when they were introduced in 2020. We didn’t know either. more how much Abogen’s vaccines could protect. recipients from developing severe symptoms of Covid.

“The lingering question around Abogen is whether it will prevent serious disease. We haven’t seen the data yet,” Bellush said.

A medical worker administers a Sinovac vaccine to a woman in eastern China’s Shandong province © AFP/Getty Images

Abogen, which raised $1.1 billion last year from investors including Singaporean investment fund Temasek and Chinese private equity group Hillhouse Capital, is also conducting preliminary trials of an mRNA vaccine candidate. which targets the BA.4 subvariant on animals, according to someone familiar with the company’s work. Abogen declined to comment.

Covid-19 mutations have also plagued Western pharmaceutical companies. But with vaccines already in use for a year and a half, Western biotechs have a head start in adapting to new variants. Pfizer and BioNTech said their Omicron-targeted vaccines elicited a strong immune response against the variant, outperforming their previous injection.

The creation of any mRNA vaccine remains very difficult. Bruce Liu, head of the life sciences division for China at consultancy Simon-Kucher & Partners, said one of the biggest challenges was developing lipid nanoparticles, the fatty shield that protects mRNA molecules that are fragile when entering human cells, and which are difficult to produce safely in large quantities.

“The devil is in the details with mRNA,” Liu said.

Not all of Abogen’s trial data has been encouraging either. About a third of the 300 trial participants developed a fever after receiving AWcorna, compared to just 4% for those who received a Sinovac booster. By comparison, 18% of recipients in a separate trial who received the Pfizer vaccine developed a fever.

A higher incidence of side effects could make it harder for health authorities to convince vaccine-hesitant people to get vaccinated — a particular problem in China, where slow uptake by older people has entrenched the authorities’ commitment to lockdowns and mass testing.

A worker in a protective suit sprays disinfectant along a line of residents awaiting Covid-19 tests.
Chinese authorities have focused on mass testing and lockdowns to fight Covid-19 © Andy Wong/AP

Problems with local mRNA vaccines could fuel calls for Beijing to turn to foreign shots. Even before BioNTech announced its partnership with Pfizer, it entered into an alliance with China’s Fosun Pharma in March 2020 to supply any successful Covid mRNA vaccine. But more than two years later, Beijing has not approved any mRNA products for therapeutic use on the mainland.

Analysts said the reluctance was politically motivated, in line with Xi’s goal of reducing reliance on foreign know-how in science and technology.

“China is allowing its domestic players to catch up, but that could turn out to be a big tactical mistake,” said an industry insider in China who declined to be named.

Even if China manages to roll out a local mRNA vaccine that’s more effective at preventing serious illness, experts said Beijing’s determination to beat the virus could make it reluctant to give up the zero-Covid restrictions that have caused an upheaval. fall in consumer spending and an increase in unemployment.

“There is no vaccine technology available that can prevent a wave of infection if China relaxes public health measures,” Cowling said. “It would be difficult for China to change course. There is so much momentum behind zero-Covid.

Additional reporting by Nian Liu and Arjun Neil Alim in Beijing and Wang Xueqiao in Shanghai

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