New Covid variants threaten mRNA vaccine hopes in China

China is making progress in developing a homegrown messenger RNA Covid-19 vaccine, but experts warn it is at risk of being outdone by rapid mutations of the Omicron coronavirus variant.

Beijing’s refusal to approve foreign jabs, and the limited effectiveness of the more traditional inactivated vaccines available from domestic companies, mean that an mRNA vaccine is widely seen as essential to any shift from the economically costly zero-covid- policies of President Xi Jinping.

Analyst optimism about the prospects for Chinese mRNA vaccines has been fueled by recent trial results for an injection 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 to Omicron at levels 4.4 times higher than those caused by the inactivated vaccine produced by Sinovac, one of China’s two major vaccine suppliers.

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

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

In a bid to increase vaccine use, health officials in Beijing announced on Wednesday that the capital’s 21 million residents must show proof of Covid vaccination for the first time from next week before entering public spaces such as movie theaters and gyms.

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 collaboration with Chinese pharmaceutical companies and undergoing clinical trials.

Success for Abogen can have consequences beyond national borders.

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

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

“There is a huge learning curve when it comes to mRNA technology, and the companies are dealing with a moving target with all these Covid strains,” said James Bellush, a medical science expert at New York-based RTW Investments.

Bellush said the emergence of new variants meant that Chinese mRNA shots would certainly not have the “earth-shattering” effectiveness against infection of the Moderna and Pfizer shots when they were first introduced in 2020. It was also not clear how much the vaccines from Abogen could protect. recipients of developing severe Covid symptoms.

“The lingering question around Abogen is whether it will prevent serious illness. 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.
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 early trials of a candidate mRNA vaccine targeting the BA, according to one person. .4 subvariant on animals. familiar with the company’s work. Abogen declined to comment.

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

Creating an mRNA vaccine remains a major challenge. Bruce Liu, head of the life sciences division for China at the consulting firm Simon-Kucher & Partners, said one of the biggest problems has been the development of lipid nanoparticles, the fatty shield that protects vulnerable mRNA molecules as they enter human cells, and which are difficult to safely produce in large quantities.

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

Also, not all of Abogen’s research data is encouraging. About a third of the 300 trial participants developed a fever after receiving AWcorna, compared with just 4 percent for those who had a Sinovac booster. In comparison, 18 percent of recipients in a separate study who received the Pfizer shot developed a fever.

A higher incidence of side effects could make it more difficult for health authorities to convince people who are hesitant about vaccines to sign up for the injection – a particular problem in China, where slow adoption by the elderly has marked the authorities’ commitment to lockdowns and mass testing. .

A worker in a protective suit sprays disinfectant past a line of residents waiting for Covid-19 testing.
Chinese authorities have targeted massive tests and lockdowns to fight Covid-19 © Andy Wong/AP

Problems with homegrown mRNA vaccines may prompt calls to Beijing to turn to foreign jabs. Even before announcing its partnership with Pfizer, BioNTech formed an alliance with China’s Fosun Pharma in March 2020 to deliver every successful Covid mRNA shot. But more than two years later, Beijing has not yet approved a single mRNA product for therapeutic use on the mainland.

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

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

Even if China manages to roll out a homegrown mRNA vaccine that’s more effective at preventing serious disease, experts say Beijing’s determination to beat the virus may make it unwilling to part with zero-tolerance. Covid restrictions that have led to a decline in consumer spending and rising 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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