Caixin
Mar 05, 2021 02:08 PM
CHINA

Tip Sheet: Key Facts to Know About China’s Vaccine Race

Philippine President Rodrigo Duterte holds up a vial of Sinovac Biotech's COVID-19 vaccine Sunday in Manila, the Philippines. Photo: VCG
Philippine President Rodrigo Duterte holds up a vial of Sinovac Biotech's COVID-19 vaccine Sunday in Manila, the Philippines. Photo: VCG

Governments around the world are picking up the pace at which they are approving and administering new vaccines in the fight against the coronavirus that has killed more than 2.5 million people and sickened more than 115 million worldwide.

Twelve vaccines are currently in use around the world, according to researchers at the London School of Hygiene and Tropical Medicine who are tracking the rollout. By their count, more than 263 million shots of the various vaccines had been administered globally as of March 1. Most are given as two jabs in the upper arm weeks apart.

Sixty-eight countries have reported they are using BioNTech/Pfizer’s mRNA vaccine, more than for any other shot. Oxford/AstraZeneca’s viral vector vaccine is being used in 55 countries. Sinopharm vaccines developed by the firm’s Beijing and Wuhan affiliates are being used in 15 and two countries, respectively, according to the countries’ officials. Sinovac’s Coronavax is in use in 11.

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Four vaccines in use in China

Four vaccines are now cleared for public use in China after the recent approval of two new shots — an inactivated-virus vaccine developed by state-owned Sinopharm's affiliate Wuhan Institute of Biological Products, and a viral vector vaccine developed by CanSino Biologics Inc. (688185.SH).

That followed earlier authorization of two other inactivated-virus vaccines separately developed by Sinopharm’s Beijing Institute of Biological Products and Sinovac Biotech Ltd.

The three inactivated-virus vaccines all require two doses, weeks apart, to reach efficacy. CanSino’s viral vector vaccine requires only one shot. All can be stored at household refrigerator temperature, but unlike other frontrunners, no Chinese vaccine has published full results from final or phase 3 clinical trials.

The world’s most populous country faces mounting pressure to accelerate vaccinations to plug the immunity gap against Covid-19 in the population, pressing vaccine-makers to accelerate production.

Output of Covid-19 vaccines in China is expected to reach 2.1 billion doses by year-end, more than one dose per person for the entire Chinese population, according to Zhang Wenhong, director of the Infectious Diseases Department at Huashan Hospital, which is affiliated with Shanghai’s Fudan University.

While China has sufficient Covid-19 vaccine production capacity, the pace and efficiency of vaccination is of “great concern,” the high profile infectious disease expert said.

China started emergency vaccinations for certain groups in June and administered 52 million doses by the end of February. The U.S., which only began giving out shots under an emergency use authorization in mid-December, had administered 75 million.

New hurdles

We can divide the race to deploy Covid-19 vaccines into three stages, each with their own hurdles, explained Feng Duojia, head of the China Association for Vaccines. The first stage was developing the vaccine, which was limited by the speed of research. Now that that safe and effective vaccines exist, we’re in the second stage — large-scale production and supply of vaccines. Once production and supply targets are met, the speed of the rollout will become the main constraint in the third stage, Feng said.

Breakout: What’s holding back vaccine production?

“Inactivated vaccines” are generated by growing and isolating the infectious SARS-CoV-2 virus and killing it, either with a physical or chemical process, to stop it from being infectious. The process preserves molecules that can prime the body’s immune system to fight an infection if the person is exposed to the virus in the wild.

Zhu Huachen, associate professor at the School of Public Health of the University of Hong Kong and deputy director of the STU-HKU Joint Institute of Virology, told Caixin that although the technology for producing such vaccines is well established, the pace of manufacturing is hampered by the need to use live virus, which must be isolated and handled in laboratories with strict biosafety controls (in China, only laboratories with the highest two standards of biosafety clearance — Level 3 and 4 — can be used).

CanSino's viral vector vaccine uses the harmless adenovirus as a vector to deliver molecules from the coronavirus into the body, which use the body’s cells to produce the necessary components to trigger an immune response. Viral vector vaccines are costly and time consuming to produce, and not particularly scalable, though new technology could change that.

The quickest and safest vaccines to produce at scale are mRNA vaccines, which carry the priming molecules’ genetic blueprints and trick body cells into making them to trigger an immune response. They don’t involve the use of live viruses. The BioNTech/Pfizer and Moderna vaccines are examples of this new technology, but Chinese versions are only in early and mid-stage trials.

“There is an immunization gap between China and other countries,” said Huashan Hospital’s Zhang. “If other countries are not able to immunize their populations well, then China will always be at risk of exposure and imported cases.”

Read more: What is limiting capacity for inactivated vaccine production?  

The "inactivated-virus vaccine" is generated by culturing and isolating the infectious SARS-CoV-2 virus and "inactivating" it by physical or chemical processes to remove pathogenicity while maintaining antigenicity. Upon injection into a healthy human body, the vaccine can stimulate the immune system to produce corresponding antibodies.

Zhu Huachen, associate professor at the School of Public Health of the University of Hong Kong and deputy director of the STU-HKU Joint Institute of Virology, told Caixin that although the production technology for inactivated vaccines is more mature than that of other vaccine types, development requires the use of the intact virus, leading to intensive isolation, culture and production processes that need to be performed in high-biosafety level P3 laboratories, which in turn sets a high requirement on the facilities and limits capacity.

Another vaccine that recently won conditional market approval in China is CanSino's viral vector vaccine. This type of vaccine uses the harmless adenovirus as a vector to express the key genetic material of SARS-CoV-2 spike protein. Upon injection of the vaccine, the human body will produce SARS-CoV-2 spike protein, triggering the immune system to produce corresponding antibodies.

There are also candidates under development based on recombinant protein technology, which uses genetic engineering to produce a large number of key SARS-CoV-2 spike proteins that stimulate the production of antibodies upon injection into the human body. Compared with more traditional routes to vaccine development, this type of vaccine does not require the intact virus for production and is therefore safer and easier to produce on a large scale.

China’s vaccine suppliers

Sinopharm’s Wuhan Institute of Biological Products: The institute’s biosafety vaccine production plant that qualified to produce a Covid-19 vaccine has a designed production capacity of 100 million doses a year, according to local newspaper the Hubei Daily.

Sinopharm’s Beijing Institute of Biological Products: The institute currently has capacity to produce 120 million doses of Covid-19 vaccines a year, according to state broadcaster CCTV. A new facility under construction will bring total annual capacity to 1 billion doses.

Sinovac: The company’s first production line for its Covid-19 vaccine started operation in late August with designed capacity of 500 million doses a year. A second line launched in February will double total capacity to 1 billion doses. But these facilities produce only high-density vaccine concentrate, which requires further processing to be proportioned, filled and packaged to become final vaccine products.

CanSino Biologics: The company's production facility in Tianjin has been expanded to reach expected annual capacity of 200 million to 250 million doses. Chairman Yu Xuefeng said that in addition to pursuing the construction of its own facilities CanSino is still looking for partners. The company is already cooperating with Shanghai Pharmaceuticals Holding Co. Ltd. to build a new plant in Shanghai with a designed annual capacity of 200 million doses. CanSino’s total annual capacity for Covid-19 vaccine production is expected to reach 500 million doses within the next few months.

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Other vaccines under development or pending commercialization in China

• Chengdu-based startup Sichuan Clover Biopharmaceuticals Inc. completed a phase 1 clinical trial for its recombinant protein vaccine and published the results in The Lancet, a medical journal. Clover said it expects to initiate a global phase 2/3 trial of its Covid-19 vaccine candidate in the first half of 2021 in a number of countries across Latin America, Asia, Europe and Africa. Interim results are expected to be released mid-year.

Clover said it built a biopharmaceutical production base in Changxing, East China’s Zhejiang province, which could potentially produce 1 billion doses a year.

• Another recombinant protein vaccine jointly developed by the Institute of Microbiology under the Chinese Academy of Sciences and Chongqing Zhifei Biological Products Co. Ltd. (300122.SZ) is in global clinic trials, according to Chinese state media. Zhifei said its annual output can reach 300 million doses.

• In March 2020, Shanghai Fosun Pharmaceutical Co. Ltd. (600196.SH) set up a partnership with BioNTech to market the German drugmaker’s mRNA vaccine in China. However, prospects for the vaccine’s rollout in the mainland are still uncertain and Chinese regulators have been tight lipped. On Feb. 27, Fosun delivered the first batch of 585,000 doses of the vaccine to Hong Kong.

• Several Chinese biotech companies are also developing mRNA vaccine candidates. The most promising ones include a shot under development by Abogen Biosciences Co. Ltd., which is in phase 2 clinical trials, and another made by Shanghai-based Stemirna Therapeutics, which is in phase 1 trials.

• In January, Advaccine (Suzhou) Biopharmaceuticals Co., Ltd. and Inovio, a U.S. vaccine manufacturer, reached an agreement to market Inovio’s DNA vaccine candidate INO-4800 in China.

The vaccine, the world’s only known DNA vaccine under development, is undergoing mid- and late-stage clinical trials in China and the U.S.

• Last summer, Shenzhen Kangtai Biological Products Co. Ltd.(300601.SZ) said it had obtained the right to commercialize AstraZeneca's viral vector vaccine in China. The company didn’t disclose any details or timetable for the potential rollout.

Contact reporter Flynn Murphy (flynnmurphy@caixin.com) and editors Joshua Dummer (joshuadummer@caixin.com), Han Wei (weihan@caixin.com) and Bob Simison (bobsimison@caixin.com)

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