CanSinoBIO vaccine production line in Tianjin Photo: Hu Yuwei/GT

CanSino Biologics (CanSinoBIO) is expected to increase the annual production capacity of its recombinant adenovirus vector COVID-19 vaccine - the only single-dose vaccine approved in China - to 200 to 300 million doses after its third plant comes into full operation, the Global Times learned during a Sunday visit to the plant in North China's Tianjin.

The 15,000-square-meter production base is in line with the international standards of Good Manufacture Practice of Medical Products (GMP), and there is an automatic line for pre-filling syringes and vials.

The production line adopts the adenovirus vector technology platform with independent intellectual property rights, which has been applied in the production of China's only approved Ebola vaccine developed by CanSinoBIO in 2017. 

The Global Times reporter saw on Sunday that the entire production line was smart - from vaccine bulk grouting to finished-product packaging - before being shipped across the country and around the world.

An advanced digital monitoring system inspected each step, with manual spot checks. Staff members wore multiple layers of protective suits and had to go through sanitization before approaching the production line. 

Vaccines produced at the plant are used in mass inoculation being rolled out in Tianjin and the surrounding region. 

The vaccine, named Ad5-nCoV, was granted approval for emergency use in countries like Mexico, Pakistan, and Hungary. 

It is also effective for the elderly, based on Phase-II and Phase-III trials which involved aged participants and saw no serious adverse reactions.

Whether a second shot is needed to boost immunity is still being studied, and the conclusions will be released in the future, a source close to CanSinoBIO told the Global Times. Some of the volunteers in Phase-I and Phase-II clinical trials of the Ad5-nCoV had already received a second booster dose, the Global Times learned.

The Ad5-nCoV vaccine is jointly developed by CanSinoBIO and researchers from the Institute of Military Medicine under the Academy of Military Sciences led by prestigious vaccine expert Chen Wei.

The vaccine can be stored and transported at temperatures of between 2 and 8 C, and production does not require level-three biosafety laboratories, which is the case with inactivated vaccines. Experts said this makes it more accessible for developing countries with limited facilities.

CanSinoBIO is among three Chinese leading vaccine developers who had applied for World Health Organization's approval for emergency use. Media reported that the WHO would review the applications of two of them - Sinopharm and Sinovac - within the next two weeks.