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China is making strides in efforts to develop a home-grown messenger RNA Covid-19 vaccine, but experts warn it risks being outdone by rapid mutations in the Omicron variant coronavirus.
Beijing’s refusal to authorize foreign vaccines 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 departure from President Xi Jinping’s economically costly zero-Covid policy is seen.
Optimism among analysts about the prospects for Chinese mRNA vaccines has been fueled by recent trial results for a vaccine being developed by start-up Suzhou Abogen Biosciences in partnership with Chinese pharmaceutical company Walvax Biotechnology and the country’s military.
According to results released in May, Abogen’s AWcorna vaccine produced 4.4 times higher antibodies against Omicron than the inactivated vaccine produced by Sinovac, one of China’s two main vaccine suppliers.
The early data from Abogen “looks very positive,” said Ben Cowling, an epidemiologist at the University of Hong Kong.
Most of the Chinese population has been vaccinated with inactivated vaccines from Sinovac and state-owned Sinopharm. Researchers have said this technology elicits a weaker immune response than mRNA vaccines that target the virus’s spike protein.
In a bid to increase vaccine uptake, health officials in Beijing announced on Wednesday that the capital’s 21 million residents will be required to show proof of a Covid vaccination to enter public spaces such as movie theaters and gyms for the first time from next week.
Helen Chen, head of China Life Sciences at LEK Consulting, said Abogen is “closest to completion” of nine mRNA vaccine candidates developed by or in partnership with Chinese pharmaceutical companies that are in clinical trials.
Abogen’s success could have repercussions beyond national borders.
The company hopes it will be able to store its vaccine at normal refrigerator temperatures, rather than needing the special low-temperature equipment needed for mRNA vaccines made by Moderna or BioNTech and Pfizer. That would make distribution in developing countries much easier.
However, experts said Abogen and other Chinese mRNA syringes have also been developed 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 circumvent natural and vaccine-induced immunity and are rapidly becoming dominant in much of the world. Studies have shown that more fully vaccinated individuals have been infected with BA.4 and BA.5 than with previous strains.
“There’s a tremendous learning curve when it comes to mRNA technology, and companies have to deal with all these strains of Covid with a moving target,” said James Belllush, a medical sciences expert at RTW Investments, based in New York.
Belllush said the emergence of new variants meant Chinese mRNA syringes certainly wouldn’t have the “earth-shattering” effectiveness against infection as the Moderna and Pfizer syringes did when they were first introduced in 2020. It’s also not clear how much Abogen’s vaccines could protect recipients from developing severe Covid symptoms.
“The enduring question regarding Abogen is whether it will prevent serious illness. We haven’t seen the data yet,” Bellush said.
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-stage trials of an mRNA vaccine candidate that targets BA, according to one person .4-subvariant aimed at animals familiar with the work of the company. Abogen declined to comment.
Covid-19 mutations have also plagued western pharmaceutical companies. But with vaccines that have been in use for a year and a half, Western biotechs 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, outperforming their previous vaccination.
Manufacturing an mRNA vaccine remains a major challenge. Bruce Liu, head of China life sciences at consultancy Simon-Kucher & Partners, said one of the biggest challenges is developing lipid nanoparticles, the fatty shield that protects fragile mRNA molecules while they are being transformed into human cells Invade cells, and those difficult to reach produce safely in large quantities.
“With mRNA, the devil is in the details,” Liu said.
Also, not all study data from Abogen were encouraging. About a third of 300 study participants developed fever after being given AWcorna, compared to just 4 percent of those who received a Sinovac booster shot. In comparison, in a separate study, 18 percent of recipients who received the Pfizer vaccine developed a fever.
A higher incidence of side effects could make it harder for public health officials to persuade vaccine-hesitant people to sign up for the shot — a particular problem in China, where slow uptake by older people has solidified authorities’ commitment to lockdowns and mass testing.
Problems with home-grown mRNA vaccines could fuel calls for Beijing to turn to overseas vaccines. In March 2020, even before announcing its partnership with Pfizer, BioNTech agreed an alliance with Chinese company Fosun Pharma to deliver every successful Covid mRNA shot. But more than two years later, Beijing has not approved any mRNA product for therapeutic use on the mainland.
Analysts said the reluctance was politically motivated, in line with Xi’s goal of reducing reliance on foreign science and technology expertise.
“China is letting its domestic players catch up, but that could prove to be a big tactical mistake,” said an industry insider in China who asked not to be named.
Even if China succeeds in introducing a home-grown mRNA vaccine that is more effective in preventing serious diseases, Beijing’s determination to defeat the virus could mean Beijing’s determination to defeat the virus means it is not ready to end the zero-Covid -Remove restrictions that have led to a collapse 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
